ℹ️ Skipped - page is already crawled
| Filter | Status | Condition | Details |
|---|---|---|---|
| HTTP status | PASS | download_http_code = 200 | HTTP 200 |
| Age cutoff | PASS | download_stamp > now() - 6 MONTH | 0 months ago |
| History drop | PASS | isNull(history_drop_reason) | No drop reason |
| Spam/ban | PASS | fh_dont_index != 1 AND ml_spam_score = 0 | ml_spam_score=0 |
| Canonical | PASS | meta_canonical IS NULL OR = '' OR = src_unparsed | Not set |
| Property | Value |
|---|---|
| URL | https://www.cuemath.com/trigonometry/sin-2pi-3/ |
| Last Crawled | 2026-04-20 06:08:28 (1 day ago) |
| First Indexed | 2021-12-09 23:25:20 (4 years ago) |
| HTTP Status Code | 200 |
| Meta Title | Sin 2pi/3 - Find Value of Sin 2pi/3 | Sin 2π/3 |
| Meta Description | Sin 2pi/3 degrees is the value of sine trigonometric function for an angle equal to 2pi/3. Understand methods to find the value of sin 2pi/3 with examples and FAQs. |
| Meta Canonical | null |
| Boilerpipe Text | The value of
sin 2pi/3 is 0.8660254. . .
. Sin 2pi/3 radians in degrees is written as sin ((2π/3) × 180°/π), i.e., sin (120°). In this article, we will discuss the methods to find the value of sin 2pi/3 with examples.
Sin 2pi/3:
√3/2
Sin 2pi/3 in decimal:
0.8660254. . .
Sin (-2pi/3):
-0.8660254. . . or -(√3/2)
Sin 2pi/3 in degrees:
sin (120°)
What is the Value of Sin 2pi/3?
The value of sin 2pi/3 in
decimal
is 0.866025403. . .. Sin 2pi/3 can also be expressed using the equivalent of the given
angle
(2pi/3) in degrees (120°).
We know, using
radian to degree
conversion, θ in degrees = θ in radians × (180°/
pi
)
⇒ 2pi/3 radians = 2pi/3 × (180°/pi) = 120° or 120
degrees
∴ sin 2pi/3 = sin 2π/3 = sin(120°) = √3/2 or 0.8660254. . .
Explanation:
For sin 2pi/3, the angle 2pi/3 lies between pi/2 and pi (Second
Quadrant
). Since sine function is positive in the second quadrant, thus sin 2pi/3 value = √3/2 or 0.8660254. . .
Since the sine function is a
periodic function
, we can represent sin 2pi/3 as, sin 2pi/3 = sin(2pi/3 + n × 2pi), n ∈ Z.
⇒ sin 2pi/3 = sin 8pi/3 = sin 14pi/3 , and so on.
Note:
Since, sine is an
odd function
, the value of sin(-2pi/3) = -sin(2pi/3).
Methods to Find Value of Sin 2pi/3
The sine function is positive in the 2nd quadrant. The value of sin 2pi/3 is given as 0.86602. . .. We can find the value of sin 2pi/3 by:
Using Unit Circle
Using Trigonometric Functions
Sin 2pi/3 Using Unit Circle
To find the value of sin 2π/3 using the unit circle:
Rotate ‘r’ anticlockwise to form 2pi/3 angle with the positive x-axis.
The sin of 2pi/3 equals the y-coordinate(0.866) of the point of intersection (-0.5, 0.866) of unit circle and r.
Hence the value of sin 2pi/3 = y = 0.866 (approx)
Sin 2pi/3 in Terms of Trigonometric Functions
Using
trigonometry
formulas, we can represent the sin 2pi/3 as:
± √(1-cos²(2pi/3))
± tan(2pi/3)/√(1 + tan²(2pi/3))
± 1/√(1 + cot²(2pi/3))
± √(sec²(2pi/3) - 1)/sec(2pi/3)
1/cosec(2pi/3)
Note:
Since 2pi/3 lies in the 2nd Quadrant, the final value of sin 2pi/3 will be positive.
We can use trigonometric identities to represent sin 2pi/3 as,
sin(pi - 2pi/3) = sin pi/3
-sin(pi + 2pi/3) = -sin 5pi/3
cos(pi/2 - 2pi/3) = cos(-pi/6)
-cos(pi/2 + 2pi/3) = -cos 7pi/6
☛ Also Check:
tan 3pi/2
sin pi/3
cos 17pi/12
tan 2pi/3
sec pi/3
sin 3pi/2
FAQs on Sin 2pi/3
What is Sin 2pi/3?
Sin 2pi/3 is the value of sine
trigonometric function
for an angle equal to 2pi/3 radians.
The value of sin 2pi/3 is √3/2 or 0.866 (approx).
What is the Value of Sin 2pi/3 in Terms of Cosec 2pi/3?
Since the
cosecant function
is the reciprocal of the
sine function
, we can write sin 2pi/3 as 1/cosec(2pi/3). The value of cosec 2pi/3 is equal to 1.15470.
How to Find Sin 2pi/3 in Terms of Other Trigonometric Functions?
Using
trigonometry formula
, the value of sin 2π/3 can be given in terms of other trigonometric functions as:
± √(1-cos²(2pi/3))
± tan(2pi/3)/√(1 + tan²(2pi/3))
± 1/√(1 + cot²(2pi/3))
± √(sec²(2pi/3) - 1)/sec(2pi/3)
1/cosec(2pi/3)
☛ Also check:
trigonometric table
How to Find the Value of Sin 2pi/3?
The value of sin 2pi/3 can be calculated by constructing an
angle
of 2π/3
radians
with the
x-axis
, and then finding the coordinates of the corresponding point (-0.5, 0.866) on the
unit circle
. The value of sin 2pi/3 is equal to the y-coordinate (0.866). ∴ sin 2pi/3 = 0.866.
What is the Value of Sin 2pi/3 in Terms of Tan 2pi/3?
We know, using
trig identities
, we can write sin 2pi/3 as -tan(2pi/3)/√(1 + tan²(2pi/3)). Here, the value of tan 2pi/3 is equal to -1.732050. |
| Markdown | [Math Tutoring](https://www.cuemath.com/math-online-classes)
[Elementary K-2](https://www.cuemath.com/math-online-classes/grade-k-2)
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2)
[Elementary 3-5](https://www.cuemath.com/math-online-classes/grade-3-5)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5)
[Middle School](https://www.cuemath.com/math-online-classes/grade-6-8)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8)
[High School](https://www.cuemath.com/math-online-classes/high-school)
[Algebra-1](https://www.cuemath.com/math-online-classes/algebra-1)
[Geometry](https://www.cuemath.com/math-online-classes/geometry)
[Algebra-2](https://www.cuemath.com/math-online-classes/algebra-2)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus)
[AP Pre-Calculus](https://www.cuemath.com/math-online-classes/ap-precalculus)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep)
[STAAR](https://www.cuemath.com/test/staar-test)
[NJSLA](https://www.cuemath.com/test/njsla-test)
[MAP](https://www.cuemath.com/test/map-test)
[Math Kangaroo](https://www.cuemath.com/test/math-kangaroo)
[CogAT](https://www.cuemath.com/test/cogat-test)
[AASA](https://www.cuemath.com/test/aasa-test)
[SBAC](https://www.cuemath.com/test/sbac-test)
[AMC 8](https://www.cuemath.com/test/amc-8-test)
[GMAS](https://www.cuemath.com/test/gmas-test)
[IAR](https://www.cuemath.com/test/iar-test)
[SSAT](https://www.cuemath.com/test/ssat-test)
[Pricing](https://www.cuemath.com/pricing)
[Resources]()
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation)
[Math Test](https://www.cuemath.com/math-test)
[Events](https://www.cuemath.com/events)
[Blogs](https://www.cuemath.com/blog)
[Cuemath App](https://www.cuemath.com/apps/cuemath?utm_source=website_navbar)
[About Us]()
[Our Impact](https://www.cuemath.com/our-impact)
[Our Tutors](https://www.cuemath.com/our-tutors)
[Our Story & Mission](https://www.cuemath.com/about-us)
[Our Reviews](https://www.cuemath.com/our-reviews)
[Cuemath Vs Others](https://www.cuemath.com/blog/tag/cuemath-vs-others)
[What is MathFit](https://www.cuemath.com/blog/what-does-it-mean-to-be-mathfit)
[FAQs](https://www.cuemath.com/frequently-asked-questions)
Get started
[Math Tutoring](https://www.cuemath.com/math-online-classes)
[Elementary K-2](https://www.cuemath.com/math-online-classes/grade-k-2)
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2)
[Elementary 3-5](https://www.cuemath.com/math-online-classes/grade-3-5)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5)
[Middle School](https://www.cuemath.com/math-online-classes/grade-6-8)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8)
[High School](https://www.cuemath.com/math-online-classes/high-school)
[Algebra-1](https://www.cuemath.com/math-online-classes/algebra-1)
[Geometry](https://www.cuemath.com/math-online-classes/geometry)
[Algebra-2](https://www.cuemath.com/math-online-classes/algebra-2)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus)
[AP Pre-Calculus](https://www.cuemath.com/math-online-classes/ap-precalculus)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep)
[STAAR](https://www.cuemath.com/test/staar-test)
[NJSLA](https://www.cuemath.com/test/njsla-test)
[MAP](https://www.cuemath.com/test/map-test)
[Math Kangaroo](https://www.cuemath.com/test/math-kangaroo)
[CogAT](https://www.cuemath.com/test/cogat-test)
[AASA](https://www.cuemath.com/test/aasa-test)
[SBAC](https://www.cuemath.com/test/sbac-test)
[AMC 8](https://www.cuemath.com/test/amc-8-test)
[GMAS](https://www.cuemath.com/test/gmas-test)
[IAR](https://www.cuemath.com/test/iar-test)
[SSAT](https://www.cuemath.com/test/ssat-test)
[Pricing](https://www.cuemath.com/pricing)
Resources
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation)
[Math Test](https://www.cuemath.com/math-test)
[Events](https://www.cuemath.com/events)
[Blogs](https://www.cuemath.com/blog)
[Cuemath App](https://www.cuemath.com/apps/cuemath?utm_source=website_navbar)
About Us
[Our Impact](https://www.cuemath.com/our-impact)
[Our Tutors](https://www.cuemath.com/our-tutors)
[Our Story & Mission](https://www.cuemath.com/about-us)
[Our Reviews](https://www.cuemath.com/our-reviews)
[Cuemath Vs Others](https://www.cuemath.com/blog/tag/cuemath-vs-others)
[What is MathFit](https://www.cuemath.com/blog/what-does-it-mean-to-be-mathfit)
[FAQs](https://www.cuemath.com/frequently-asked-questions)
[Learn]()[Practice]()[Download]()
# Sin 2pi/3
The value of **sin 2pi/3 is 0.8660254. . .**. Sin 2pi/3 radians in degrees is written as sin ((2π/3) × 180°/π), i.e., sin (120°). In this article, we will discuss the methods to find the value of sin 2pi/3 with examples.
- **Sin 2pi/3:** √3/2
- **Sin 2pi/3 in decimal:** 0.8660254. . .
- **Sin (-2pi/3):** -0.8660254. . . or -(√3/2)
- **Sin 2pi/3 in degrees:** sin (120°)
## What is the Value of Sin 2pi/3?
The value of sin 2pi/3 in [decimal](https://www.cuemath.com/numbers/decimals/) is 0.866025403. . .. Sin 2pi/3 can also be expressed using the equivalent of the given [angle](https://www.cuemath.com/geometry/angles/) (2pi/3) in degrees (120°).
We know, using [radian to degree](https://www.cuemath.com/geometry/radians-to-degrees/) conversion, θ in degrees = θ in radians × (180°/[pi](https://www.cuemath.com/geometry/what-is-pi/))
⇒ 2pi/3 radians = 2pi/3 × (180°/pi) = 120° or 120 [degrees](https://www.cuemath.com/geometry/degrees/)
∴ sin 2pi/3 = sin 2π/3 = sin(120°) = √3/2 or 0.8660254. . .

**Explanation:**
For sin 2pi/3, the angle 2pi/3 lies between pi/2 and pi (Second [Quadrant](https://www.cuemath.com/geometry/quadrant/)). Since sine function is positive in the second quadrant, thus sin 2pi/3 value = √3/2 or 0.8660254. . .
Since the sine function is a [periodic function](https://www.cuemath.com/algebra/periodic-function/), we can represent sin 2pi/3 as, sin 2pi/3 = sin(2pi/3 + n × 2pi), n ∈ Z.
⇒ sin 2pi/3 = sin 8pi/3 = sin 14pi/3 , and so on.
**Note:** Since, sine is an [odd function](https://www.cuemath.com/calculus/odd-functions/), the value of sin(-2pi/3) = -sin(2pi/3).
## Methods to Find Value of Sin 2pi/3
The sine function is positive in the 2nd quadrant. The value of sin 2pi/3 is given as 0.86602. . .. We can find the value of sin 2pi/3 by:
- Using Unit Circle
- Using Trigonometric Functions
## Sin 2pi/3 Using Unit Circle

To find the value of sin 2π/3 using the unit circle:
- Rotate ‘r’ anticlockwise to form 2pi/3 angle with the positive x-axis.
- The sin of 2pi/3 equals the y-coordinate(0.866) of the point of intersection (-0.5, 0.866) of unit circle and r.
Hence the value of sin 2pi/3 = y = 0.866 (approx)
## Sin 2pi/3 in Terms of Trigonometric Functions
Using [trigonometry](https://www.cuemath.com/trigonometry/) formulas, we can represent the sin 2pi/3 as:
- ± √(1-cos²(2pi/3))
- ± tan(2pi/3)/√(1 + tan²(2pi/3))
- ± 1/√(1 + cot²(2pi/3))
- ± √(sec²(2pi/3) - 1)/sec(2pi/3)
- 1/cosec(2pi/3)
**Note:** Since 2pi/3 lies in the 2nd Quadrant, the final value of sin 2pi/3 will be positive.
We can use trigonometric identities to represent sin 2pi/3 as,
- sin(pi - 2pi/3) = sin pi/3
- \-sin(pi + 2pi/3) = -sin 5pi/3
- cos(pi/2 - 2pi/3) = cos(-pi/6)
- \-cos(pi/2 + 2pi/3) = -cos 7pi/6
**☛ Also Check:**
- [tan 3pi/2](https://www.cuemath.com/trigonometry/tan-3pi-2/)
- [sin pi/3](https://www.cuemath.com/trigonometry/sin-pi-3/)
- [cos 17pi/12](https://www.cuemath.com/trigonometry/cos-17pi-12/)
- [tan 2pi/3](https://www.cuemath.com/trigonometry/tan-2pi-3/)
- [sec pi/3](https://www.cuemath.com/trigonometry/sec-pi-3/)
- [sin 3pi/2](https://www.cuemath.com/trigonometry/sin-3pi-2/)
## Examples Using Sin 2pi/3
1. **Example 1: Using the value of sin 2pi/3, solve: (1-cos²(2pi/3)).**
**Solution:**
We know, (1-cos²(2pi/3)) = (sin²(2pi/3)) = 0.75
⇒ (1-cos²(2pi/3)) = 0.75
2. **Example 2: Simplify: 7 (sin(2pi/3)/sin(8pi/3))**
**Solution:**
We know sin 2pi/3 = sin 8pi/3
⇒ 7 sin(2pi/3)/sin(8pi/3) = 7(sin(2pi/3)/sin(2pi/3))
= 7(1) = 7
3. **Example 3: Find the value of 5 sin(2pi/3)/7 cos(-pi/6).**
**Solution:**
Using trigonometric identities, we know, sin(2pi/3) = cos(pi/2 - 2pi/3) = cos(-pi/6).
⇒ sin(2pi/3) = cos(-pi/6)
⇒ Value of 5 sin(2pi/3)/7 cos(-pi/6) = 5/7
Show Solution \>
[go to slide](https://www.cuemath.com/trigonometry/sin-2pi-3/#slide-913)[go to slide](https://www.cuemath.com/trigonometry/sin-2pi-3/#slide-493)[go to slide](https://www.cuemath.com/trigonometry/sin-2pi-3/#slide-999)

Ready to see the world through math’s eyes?
Math is at the core of everything we do. Enjoy solving real-world math problems in live classes and become an expert at everything.
[Book a Free Trial Class](https://www.cuemath.com/parent/signup/)
## FAQs on Sin 2pi/3
### What is Sin 2pi/3?
Sin 2pi/3 is the value of sine [trigonometric function](https://www.cuemath.com/trigonometry/trigonometric-functions/) for an angle equal to 2pi/3 radians. ***The value of sin 2pi/3 is √3/2 or 0.866 (approx).***
### What is the Value of Sin 2pi/3 in Terms of Cosec 2pi/3?
Since the [cosecant function](https://www.cuemath.com/trigonometry/cosecant-functions/) is the reciprocal of the [sine function](https://www.cuemath.com/trigonometry/sine-function/), we can write sin 2pi/3 as 1/cosec(2pi/3). The value of cosec 2pi/3 is equal to 1.15470.
### How to Find Sin 2pi/3 in Terms of Other Trigonometric Functions?
Using [trigonometry formula](https://www.cuemath.com/trigonometry/trigonometry-formula/), the value of sin 2π/3 can be given in terms of other trigonometric functions as:
- ± √(1-cos²(2pi/3))
- ± tan(2pi/3)/√(1 + tan²(2pi/3))
- ± 1/√(1 + cot²(2pi/3))
- ± √(sec²(2pi/3) - 1)/sec(2pi/3)
- 1/cosec(2pi/3)
☛ Also check: [trigonometric table](https://www.cuemath.com/trigonometry/trigonometric-table/)
### How to Find the Value of Sin 2pi/3?
The value of sin 2pi/3 can be calculated by constructing an [angle](https://www.cuemath.com/geometry/angles/) of 2π/3 [radians](https://www.cuemath.com/trigonometry/what-is-a-radian/) with the [x-axis](https://www.cuemath.com/geometry/x-and-y-axis/), and then finding the coordinates of the corresponding point (-0.5, 0.866) on the [unit circle](https://www.cuemath.com/geometry/unit-circle/). The value of sin 2pi/3 is equal to the y-coordinate (0.866). ∴ sin 2pi/3 = 0.866.
### What is the Value of Sin 2pi/3 in Terms of Tan 2pi/3?
We know, using [trig identities](https://www.cuemath.com/trigonometry/trigonometric-identities/), we can write sin 2pi/3 as -tan(2pi/3)/√(1 + tan²(2pi/3)). Here, the value of tan 2pi/3 is equal to -1.732050.
Explore
math program
Download FREE Study Materials
Trigonometry
Explore
math program
Math worksheets and
visual curriculum
Book a FREE Class
Become MathFit™:
Boost math skills with daily fun challenges and puzzles.
Download the app
STRATEGY GAMES
LOGIC PUZZLES
MENTAL MATH
Become MathFit™:
Boost math skills with daily fun challenges and puzzles.
Download the app
STRATEGY GAMES
LOGIC PUZZLES
MENTAL MATH
US Office
CueLearn Inc, 1013 Centre Road, Suite 403-B, Wilmington, Delaware 19805
India Office
Plot No. F-17/5, Golf Course Rd, Sector 42, Gurugram, Haryana 122009
US Office
CueLearn Inc, 1013 Centre Road, Suite 403-B, Wilmington, Delaware 19805
India Office
Plot No. F-17/5, Golf Course Rd, Sector 42, Gurugram, Haryana 122009

[Terms & conditions](https://www.cuemath.com/terms)
[Privacy Policy](https://www.cuemath.com/privacy)
[](https://www.facebook.com/cuemath/)[](https://www.youtube.com/channel/UC24sjKTMy-d5Z-g2OsYYHqw)[](https://www.instagram.com/cuemath/)[](https://x.com/cuemath)[](https://www.linkedin.com/company/cue-learn/)
[](https://www.facebook.com/cuemath/)[](https://www.youtube.com/channel/UC24sjKTMy-d5Z-g2OsYYHqw)[](https://www.instagram.com/cuemath/)[](https://x.com/cuemath)[](https://www.linkedin.com/company/cue-learn/)

[Terms & conditions](https://www.cuemath.com/terms)
[Privacy Policy](https://www.cuemath.com/privacy)
ABOUT CUEMATH
[About Us](https://www.cuemath.com/about-us/)
[Our Impact](https://www.cuemath.com/our-impact/)
[Our Tutors](https://www.cuemath.com/our-tutors/)
[Our Reviews](https://www.cuemath.com/our-reviews/)
[FAQs](https://www.cuemath.com/frequently-asked-questions/)
[Pricing](https://www.cuemath.com/pricing/)
[Contact Us](https://www.cuemath.com/contact-us/)
[Refund Policy](https://www.cuemath.com/refund-policy/)
ABOUT CUEMATH
\+
[About Us](https://www.cuemath.com/about-us/)
[Our Impact](https://www.cuemath.com/our-impact/)
[Our Tutors](https://www.cuemath.com/our-tutors/)
[Our Reviews](https://www.cuemath.com/our-reviews/)
[FAQs](https://www.cuemath.com/frequently-asked-questions/)
[Pricing](https://www.cuemath.com/pricing/)
[Contact Us](https://www.cuemath.com/contact-us/)
[Refund Policy](https://www.cuemath.com/refund-policy/)
OUR PROGRAMS
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten/)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1/)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2/)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3/)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4/)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5/)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6/)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7/)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8/)
[Algebra 1](https://www.cuemath.com/math-online-classes/algebra-1/)
[Algebra 2](https://www.cuemath.com/math-online-classes/algebra-2/)
[Geometry](https://www.cuemath.com/math-online-classes/geometry/)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus/)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus/)
[Cueprep](http://cueprep.com/)
OUR PROGRAMS
\+
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten/)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1/)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2/)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3/)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4/)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5/)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6/)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7/)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8/)
[Algebra 1](https://www.cuemath.com/math-online-classes/algebra-1/)
[Algebra 2](https://www.cuemath.com/math-online-classes/algebra-2/)
[Geometry](https://www.cuemath.com/math-online-classes/geometry/)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus/)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus/)
[Cueprep](http://cueprep.com/)
RESOURCES
[Blogs](https://www.cuemath.com/blog/)
[Math Puzzles](https://www.cuemath.com/math-puzzles/)
[MathFit™ 100 Puzzles](https://d138zd1ktt9iqe.cloudfront.net/static/website-v3/puzzle-booklet.pdf)
[Math Test](https://www.cuemath.com/math-test/)
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation/)
RESOURCES
\+
[Blogs](https://www.cuemath.com/blog/)
[Math Puzzles](https://www.cuemath.com/math-puzzles/)
[MathFit™ 100 Puzzles](https://d138zd1ktt9iqe.cloudfront.net/static/website-v3/puzzle-booklet.pdf)
[Math Test](https://www.cuemath.com/math-test/)
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation/)
EVENTS
[Math Fests](https://www.cuemath.com/events/math/)
EVENTS
\+
[Math Fests](https://www.cuemath.com/events/math/)
MATH TUTORING
[Online Math Classes](https://www.cuemath.com/math-online-classes/)
[Online Math Courses](https://www.cuemath.com/online-math-courses/)
[Online Math Tutors](https://www.cuemath.com/online-math-tutor/)
[Summer Math Courses](https://www.cuemath.com/summer-math-courses/)
[Math Tutors near me](https://www.cuemath.com/math-tutors-near-me/)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep/)
[Math Tuition](https://www.cuemath.com/math-tuition-india/)
[Math Tutors India](https://www.cuemath.com/math-tutors-india/)
MATH TUTORING
\+
[Online Math Classes](https://www.cuemath.com/math-online-classes/)
[Online Math Courses](https://www.cuemath.com/online-math-courses/)
[Online Math Tutors](https://www.cuemath.com/online-math-tutor/)
[Summer Math Courses](https://www.cuemath.com/summer-math-courses/)
[Math Tutors near me](https://www.cuemath.com/math-tutors-near-me/)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep/)
[Math Tuition](https://www.cuemath.com/math-tuition-india/)
[Math Tutors India](https://www.cuemath.com/math-tutors-india/)
PARTNER WITH US
[Become a volunteer/affiliate](https://www.cuemath.com/affiliate/)
PARTNER WITH US
\+
[Become a volunteer/affiliate](https://www.cuemath.com/affiliate/)
Become MathFit™:
Boost math skills with daily fun challenges and puzzles.
Download the app
STRATEGY GAMES
LOGIC PUZZLES
MENTAL MATH
Become MathFit™:
Boost math skills with daily fun challenges and puzzles.
Download the app
STRATEGY GAMES
LOGIC PUZZLES
MENTAL MATH
ABOUT CUEMATH
[About Us](https://www.cuemath.com/about-us/)
[Our Impact](https://www.cuemath.com/our-impact/)
[Our Tutors](https://www.cuemath.com/our-tutors/)
[Our Reviews](https://www.cuemath.com/our-reviews/)
[FAQs](https://www.cuemath.com/frequently-asked-questions/)
[Pricing](https://www.cuemath.com/pricing/)
[Contact Us](https://www.cuemath.com/contact-us/)
[Refund Policy](https://www.cuemath.com/refund-policy/)
ABOUT CUEMATH
\+
[About Us](https://www.cuemath.com/about-us/)
[Our Impact](https://www.cuemath.com/our-impact/)
[Our Tutors](https://www.cuemath.com/our-tutors/)
[Our Reviews](https://www.cuemath.com/our-reviews/)
[FAQs](https://www.cuemath.com/frequently-asked-questions/)
[Pricing](https://www.cuemath.com/pricing/)
[Contact Us](https://www.cuemath.com/contact-us/)
[Refund Policy](https://www.cuemath.com/refund-policy/)
OUR PROGRAMS
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten/)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1/)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2/)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3/)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4/)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5/)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6/)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7/)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8/)
[Algebra 1](https://www.cuemath.com/math-online-classes/algebra-1/)
[Algebra 2](https://www.cuemath.com/math-online-classes/algebra-2/)
[Geometry](https://www.cuemath.com/math-online-classes/geometry/)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus/)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus/)
[Cueprep](http://cueprep.com/)
OUR PROGRAMS
\+
[Kindergarten](https://www.cuemath.com/math-online-classes/kindergarten/)
[Grade 1](https://www.cuemath.com/math-online-classes/grade-1/)
[Grade 2](https://www.cuemath.com/math-online-classes/grade-2/)
[Grade 3](https://www.cuemath.com/math-online-classes/grade-3/)
[Grade 4](https://www.cuemath.com/math-online-classes/grade-4/)
[Grade 5](https://www.cuemath.com/math-online-classes/grade-5/)
[Grade 6](https://www.cuemath.com/math-online-classes/grade-6/)
[Grade 7](https://www.cuemath.com/math-online-classes/grade-7/)
[Grade 8](https://www.cuemath.com/math-online-classes/grade-8/)
[Algebra 1](https://www.cuemath.com/math-online-classes/algebra-1/)
[Algebra 2](https://www.cuemath.com/math-online-classes/algebra-2/)
[Geometry](https://www.cuemath.com/math-online-classes/geometry/)
[Pre-Calculus](https://www.cuemath.com/math-online-classes/pre-calculus/)
[AP Calculus](https://www.cuemath.com/math-online-classes/ap-calculus/)
[Cueprep](http://cueprep.com/)
RESOURCES
[Blogs](https://www.cuemath.com/blog/)
[Math Puzzles](https://www.cuemath.com/math-puzzles/)
[MathFit™ 100 Puzzles](https://d138zd1ktt9iqe.cloudfront.net/static/website-v3/puzzle-booklet.pdf)
[Math Test](https://www.cuemath.com/math-test/)
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation/)
RESOURCES
\+
[Blogs](https://www.cuemath.com/blog/)
[Math Puzzles](https://www.cuemath.com/math-puzzles/)
[MathFit™ 100 Puzzles](https://d138zd1ktt9iqe.cloudfront.net/static/website-v3/puzzle-booklet.pdf)
[Math Test](https://www.cuemath.com/math-test/)
[MathFit Evaluation](https://www.cuemath.com/mathfit-evaluation/)
EVENTS
[Math Fests](https://www.cuemath.com/events/math/)
EVENTS
\+
[Math Fests](https://www.cuemath.com/events/math/)
MATH TUTORING
[Online Math Classes](https://www.cuemath.com/math-online-classes/)
[Online Math Courses](https://www.cuemath.com/online-math-courses/)
[Online Math Tutors](https://www.cuemath.com/online-math-tutor/)
[Summer Math Courses](https://www.cuemath.com/summer-math-courses/)
[Math Tutors near me](https://www.cuemath.com/math-tutors-near-me/)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep/)
[Math Tuition](https://www.cuemath.com/math-tuition-india/)
[Math Tutors India](https://www.cuemath.com/math-tutors-india/)
MATH TUTORING
\+
[Online Math Classes](https://www.cuemath.com/math-online-classes/)
[Online Math Courses](https://www.cuemath.com/online-math-courses/)
[Online Math Tutors](https://www.cuemath.com/online-math-tutor/)
[Summer Math Courses](https://www.cuemath.com/summer-math-courses/)
[Math Tutors near me](https://www.cuemath.com/math-tutors-near-me/)
[Test Prep](https://www.cuemath.com/math-online-classes/test-prep/)
[Math Tuition](https://www.cuemath.com/math-tuition-india/)
[Math Tutors India](https://www.cuemath.com/math-tutors-india/)
PARTNER WITH US
[Become a volunteer/affiliate](https://www.cuemath.com/affiliate/)
PARTNER WITH US
\+
[Become a volunteer/affiliate](https://www.cuemath.com/affiliate/)
US Office
CueLearn Inc, 1013 Centre Road, Suite 403-B, Wilmington, Delaware 19805
India Office
Plot No. F-17/5, Golf Course Rd, Sector 42, Gurugram, Haryana 122009
US Office
CueLearn Inc, 1013 Centre Road, Suite 403-B, Wilmington, Delaware 19805
India Office
Plot No. F-17/5, Golf Course Rd, Sector 42, Gurugram, Haryana 122009

[Terms & conditions](https://www.cuemath.com/terms)
[Privacy Policy](https://www.cuemath.com/privacy)
[](https://www.facebook.com/cuemath/)[](https://www.youtube.com/channel/UC24sjKTMy-d5Z-g2OsYYHqw)[](https://www.instagram.com/cuemath/)[](https://x.com/cuemath)[](https://www.linkedin.com/company/cue-learn/)
[](https://www.facebook.com/cuemath/)[](https://www.youtube.com/channel/UC24sjKTMy-d5Z-g2OsYYHqw)[](https://www.instagram.com/cuemath/)[](https://x.com/cuemath)[](https://www.linkedin.com/company/cue-learn/)

[Terms & conditions](https://www.cuemath.com/terms)
[Privacy Policy](https://www.cuemath.com/privacy) |
| Readable Markdown | The value of **sin 2pi/3 is 0.8660254. . .**. Sin 2pi/3 radians in degrees is written as sin ((2π/3) × 180°/π), i.e., sin (120°). In this article, we will discuss the methods to find the value of sin 2pi/3 with examples.
- **Sin 2pi/3:** √3/2
- **Sin 2pi/3 in decimal:** 0.8660254. . .
- **Sin (-2pi/3):** -0.8660254. . . or -(√3/2)
- **Sin 2pi/3 in degrees:** sin (120°)
## What is the Value of Sin 2pi/3?
The value of sin 2pi/3 in [decimal](https://www.cuemath.com/numbers/decimals/) is 0.866025403. . .. Sin 2pi/3 can also be expressed using the equivalent of the given [angle](https://www.cuemath.com/geometry/angles/) (2pi/3) in degrees (120°).
We know, using [radian to degree](https://www.cuemath.com/geometry/radians-to-degrees/) conversion, θ in degrees = θ in radians × (180°/[pi](https://www.cuemath.com/geometry/what-is-pi/))
⇒ 2pi/3 radians = 2pi/3 × (180°/pi) = 120° or 120 [degrees](https://www.cuemath.com/geometry/degrees/)
∴ sin 2pi/3 = sin 2π/3 = sin(120°) = √3/2 or 0.8660254. . .

**Explanation:**
For sin 2pi/3, the angle 2pi/3 lies between pi/2 and pi (Second [Quadrant](https://www.cuemath.com/geometry/quadrant/)). Since sine function is positive in the second quadrant, thus sin 2pi/3 value = √3/2 or 0.8660254. . .
Since the sine function is a [periodic function](https://www.cuemath.com/algebra/periodic-function/), we can represent sin 2pi/3 as, sin 2pi/3 = sin(2pi/3 + n × 2pi), n ∈ Z.
⇒ sin 2pi/3 = sin 8pi/3 = sin 14pi/3 , and so on.
**Note:** Since, sine is an [odd function](https://www.cuemath.com/calculus/odd-functions/), the value of sin(-2pi/3) = -sin(2pi/3).
## Methods to Find Value of Sin 2pi/3
The sine function is positive in the 2nd quadrant. The value of sin 2pi/3 is given as 0.86602. . .. We can find the value of sin 2pi/3 by:
- Using Unit Circle
- Using Trigonometric Functions
## Sin 2pi/3 Using Unit Circle

To find the value of sin 2π/3 using the unit circle:
- Rotate ‘r’ anticlockwise to form 2pi/3 angle with the positive x-axis.
- The sin of 2pi/3 equals the y-coordinate(0.866) of the point of intersection (-0.5, 0.866) of unit circle and r.
Hence the value of sin 2pi/3 = y = 0.866 (approx)
## Sin 2pi/3 in Terms of Trigonometric Functions
Using [trigonometry](https://www.cuemath.com/trigonometry/) formulas, we can represent the sin 2pi/3 as:
- ± √(1-cos²(2pi/3))
- ± tan(2pi/3)/√(1 + tan²(2pi/3))
- ± 1/√(1 + cot²(2pi/3))
- ± √(sec²(2pi/3) - 1)/sec(2pi/3)
- 1/cosec(2pi/3)
**Note:** Since 2pi/3 lies in the 2nd Quadrant, the final value of sin 2pi/3 will be positive.
We can use trigonometric identities to represent sin 2pi/3 as,
- sin(pi - 2pi/3) = sin pi/3
- \-sin(pi + 2pi/3) = -sin 5pi/3
- cos(pi/2 - 2pi/3) = cos(-pi/6)
- \-cos(pi/2 + 2pi/3) = -cos 7pi/6
**☛ Also Check:**
- [tan 3pi/2](https://www.cuemath.com/trigonometry/tan-3pi-2/)
- [sin pi/3](https://www.cuemath.com/trigonometry/sin-pi-3/)
- [cos 17pi/12](https://www.cuemath.com/trigonometry/cos-17pi-12/)
- [tan 2pi/3](https://www.cuemath.com/trigonometry/tan-2pi-3/)
- [sec pi/3](https://www.cuemath.com/trigonometry/sec-pi-3/)
- [sin 3pi/2](https://www.cuemath.com/trigonometry/sin-3pi-2/)
## FAQs on Sin 2pi/3
### What is Sin 2pi/3?
Sin 2pi/3 is the value of sine [trigonometric function](https://www.cuemath.com/trigonometry/trigonometric-functions/) for an angle equal to 2pi/3 radians. ***The value of sin 2pi/3 is √3/2 or 0.866 (approx).***
### What is the Value of Sin 2pi/3 in Terms of Cosec 2pi/3?
Since the [cosecant function](https://www.cuemath.com/trigonometry/cosecant-functions/) is the reciprocal of the [sine function](https://www.cuemath.com/trigonometry/sine-function/), we can write sin 2pi/3 as 1/cosec(2pi/3). The value of cosec 2pi/3 is equal to 1.15470.
### How to Find Sin 2pi/3 in Terms of Other Trigonometric Functions?
Using [trigonometry formula](https://www.cuemath.com/trigonometry/trigonometry-formula/), the value of sin 2π/3 can be given in terms of other trigonometric functions as:
- ± √(1-cos²(2pi/3))
- ± tan(2pi/3)/√(1 + tan²(2pi/3))
- ± 1/√(1 + cot²(2pi/3))
- ± √(sec²(2pi/3) - 1)/sec(2pi/3)
- 1/cosec(2pi/3)
☛ Also check: [trigonometric table](https://www.cuemath.com/trigonometry/trigonometric-table/)
### How to Find the Value of Sin 2pi/3?
The value of sin 2pi/3 can be calculated by constructing an [angle](https://www.cuemath.com/geometry/angles/) of 2π/3 [radians](https://www.cuemath.com/trigonometry/what-is-a-radian/) with the [x-axis](https://www.cuemath.com/geometry/x-and-y-axis/), and then finding the coordinates of the corresponding point (-0.5, 0.866) on the [unit circle](https://www.cuemath.com/geometry/unit-circle/). The value of sin 2pi/3 is equal to the y-coordinate (0.866). ∴ sin 2pi/3 = 0.866.
### What is the Value of Sin 2pi/3 in Terms of Tan 2pi/3?
We know, using [trig identities](https://www.cuemath.com/trigonometry/trigonometric-identities/), we can write sin 2pi/3 as -tan(2pi/3)/√(1 + tan²(2pi/3)). Here, the value of tan 2pi/3 is equal to -1.732050. |
| Shard | 185 (laksa) |
| Root Hash | 6203651625873809585 |
| Unparsed URL | com,cuemath!www,/trigonometry/sin-2pi-3/ s443 |