Trigonometry Solver
Solve any right triangle in seconds. Pick any two known values — sides a, b, c or acute angles A, B — and get every side, every angle, the six trig ratios, a labeled diagram, and the full working.
Enter two known values
In a right triangle: a and b are the legs, c is the hypotenuse, A and B are the acute angles, and the third angle is 90°. At least one known value must be a side.
Solution
Sides
| Side a (leg) | |
|---|---|
| Side b (leg) | |
| Side c (hypotenuse) |
Angles
| Angle A | |
|---|---|
| Angle B | |
| Angle C | 90° |
Six trigonometric ratios of angle A
| sin A | cos A | tan A | csc A | sec A | cot A |
|---|---|---|---|---|---|
Diagram
Step by step working
How to use
- Choose the two values you already know from the dropdowns, for example side a and side b.
- Type their numbers. Sides must be positive; angles must be between 0 and 90 degrees.
- Press Solve Triangle. Every missing side and angle is calculated instantly.
- Read the trig ratios, study the labeled diagram, and follow the steps to learn the method.
Note: remember that the hypotenuse c is always the longest side. If you enter a leg longer than the hypotenuse, the solver will tell you the input is impossible.
Tips
- SOH CAH TOA is the memory trick: Sine = Opposite / Hypotenuse, Cosine = Adjacent / Hypotenuse, Tangent = Opposite / Adjacent.
- The two acute angles always add up to 90 degrees, so finding one gives you the other for free.
- When you know a side and an angle, the formulas sin, cos and tan connect them directly — no Pythagoras needed.
- Check your answer: the largest angle must sit opposite the longest side, which is always c.