The side opposite the right angle of a right triangle is called the hypotenuse. The sides that form the right angle are called legs.

The right angle is the largest angle in a right triangle, so the hypotenuse is the longest side of the triangle. The hypotenuse of a right triangle can be found using the Pythagorean Theorem.

For a right triangle with a hypotenuse of length c and leg lengths a and b:

c2 = a2 + b2


Find the hypotenuse length of the triangle below.

Given legs a =15 and b = 20:

c2 = 152 + 202

c2 = 625

c = 25

So, the hypotenuse length is 25.