# Triangle Hypotenuse Calculator

Calculate the length of the hypotenuse in a right triangle using two sides or one side and one angle with the calculator below.

## How to Calculate the Hypotenuse of a Right Triangle

The hypotenuse is the side in a right triangle that is opposite the 90° right angle. It’s also the longest side of the triangle.

The hypotenuse is side *c* in the illustration of a right triangle shown below.

The hypotenuse can be solved using one of the following formulas.

### Solve the Hypotenuse using Two Sides

The Pythagorean theorem can be used to solve the hypotenuse using two sides. The Pythagorean theorem states a² + b² = c².

This formula can be rewritten to solve for the hypotenuse *c*.

c = a² + b²

Thus, the hypotenuse *c* is equal to the square root of *a* squared plus *b* squared.

### Solve the Hypotenuse using One Side and the Adjacent Angle

Given one side and the adjacent angle, the following formula can be used to find the hypotenuse.

c = acos(β)

The hypotenuse *c* is equal to side *a* divided by the cosine of the adjacent angle *β*.

### Solve the Hypotenuse using One Side and the Opposite Angle

Given one side and the opposite angle, the following formula can be used to solve the hypotenuse.

c = asin(α)

The hypotenuse *c* is equal to side *a* divided by the sine of the opposite angle *α*.