Right Triangle Calculator
A complete right triangle solver. Given any two values (sides or non-right angles), this calculator finds all remaining sides and angles. Use trigonometric relationships: sin(A) = a/c, cos(A) = b/c, tan(A) = a/b, where c is the hypotenuse, A is an angle, and a and b are legs. Angle C is always 90 degrees, and angles A and B sum to 90 degrees.
Right triangle trigonometry
sin(A) = a/c (opposite/hypotenuse)
cos(A) = b/c (adjacent/hypotenuse)
tan(A) = a/b (opposite/adjacent)
Angle C = 90° (always)
Angle A + Angle B = 90°
Pythagoras: c² = a² + b²
Reference trigonometry values
| Angle | sin | cos | tan |
|---|---|---|---|
| 30° | 0.50 | 0.87 | 0.58 |
| 45° | 0.71 | 0.71 | 1.00 |
| 60° | 0.87 | 0.50 | 1.73 |
Right triangle calculator: frequently asked questions
What can this calculator solve?
Given any two values (sides or angles), the calculator finds all remaining sides and angles of a right triangle.
What are the trigonometric relationships?
sin(A) = a/c, cos(A) = b/c, tan(A) = a/b, where c is hypotenuse, A is angle opposite side a.
What is angle C?
Angle C is always 90 degrees in a right triangle. Angles A and B sum to 90 degrees.
Can I mix sides and angles?
Yes. You can give one side and one angle (besides the right angle) to solve the entire triangle.
What uses right triangles?
Construction, surveying, navigation, and physics all depend on right triangle calculations.
Official sources
- Khan Academy: Trigonometric ratios.
- NIST: National Institute of Standards.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.