Pythagorean Theorem Calculator

Calculate the third side of a right triangle when two sides are known. Calculate hypotenuse or leg length with triangle visualization.

Select Calculation Type

Choose which side to calculate.

Find Hypotenuse (Calculate c from a and b)

Enter lengths of both sides:

c² = a² + b²
Pythagorean Theorem: a² + b² = c²

Pythagorean Theorem

In a right triangle, the Pythagorean theorem states that the square of the hypotenuse (c) is equal to the sum of squares of the two legs (a, b). c² = a² + b²