Right Triangle Calculator

Solve a right triangle from its two legs — hypotenuse, angles, area, and perimeter. Enter the two legs.

Hypotenuse
—
Longest side.

Usage Tip

In a right triangle, the two non-right angles are complementary — they always add up to 90 degrees.

THE MATH
hypotenuse = √(a² + b²)
angle A = arctan(a ÷ b), area = (1 ÷ 2) a×b
A right triangle has one 90-degree angle. From the two legs, the hypotenuse comes from the Pythagorean theorem and the acute angles from inverse tangent.
The two acute angles always sum to 90 degrees.
Enter the two legs (the sides meeting at the right angle).
Angle A is opposite leg a; angle B is its complement.
Area is half the product of the legs.
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