Right Triangle Side & Angle Calculator

Give any two of: leg a, leg b, hypotenuse c, or angle A — the calculator solves everything else.

Fill exactly two boxes; leave the rest empty.

How It Works

With any two independent values, a right triangle is fully determined. Two sides use the Pythagorean theorem (a² + b² = c²); a side plus an acute angle uses sine, cosine, or tangent. Angle A is taken opposite leg a.

Frequently Asked Questions

Which side is the hypotenuse?

Side c — always opposite the right angle and always the longest side.

Why must angle A be under 90°?

The other two angles of a right triangle are acute; they add to exactly 90°.

Can it solve from the two acute angles alone?

No — angles fix only the shape, not the size. At least one side length is required.