Right Triangle Calculator

Solve a right triangle from any two sides — angles, area and perimeter.

Enter any two of the three sides; leave the unknown blank.
Clear

Solving a right triangle

A right triangle has one 90° angle. Given any two sides, the third follows from the Pythagorean theorem: a² + b² = c², where c is the hypotenuse (the longest side, opposite the right angle).

The two non-right angles are found with the arctangent of the opposite over the adjacent side, and always sum to 90°. The area of a right triangle is simply half the product of its two legs.