Trigonometry Calculator
Evaluate sin, cos or tan of an angle in degrees or radians. Standard angles (multiples of 30° and 45°, or π/6, π/4, …) get exact values using reference angles and quadrant signs; others are given to 6 decimal places. The right-triangle solver finds the missing sides and angles from any two values using Pythagoras and SOH-CAH-TOA.
Step-by-step
waitingFill in the fields and press Solve. The full method will appear here, one numbered step at a time.
Worked example
Find the exact value of sin(150°).
- 1.
Angle θ = 150°. sin θ is the y-coordinate of the point at angle θ on the unit circle.
- 2.
150° is in quadrant II. Its reference angle (the angle to the x-axis) is 30°, and sin is positive in that quadrant (All–Sin–Tan–Cos rule).
- 3.
Use the exact value from the 30-60-90 triangle.
sin(30°) = 1/2
- 4.
Apply the sign.
sin(150°) = 1/2
Answer: sin(150°) = 1/2
Note: Exact values for multiples of 30° and 45°; other angles are rounded to 6 decimal places and marked ≈.
Use “Load worked example” above to run this in the solver.
Related formulas
The formulas this tool uses, each explained with symbols, conditions and its own example in the Formula Library.