Note: We get a positive and a negative answer when we take a square root. However, lengths of sides can never be negative so we take the positive square root.

Example 2

A right-angled triangle has hypotenuse of length $9$ and a side of length $3$. Find the length of the other side.

Solution

This time we are given the length of the hypotenuse and one of the other sides is unknown. Start by rearranging the Pythagorean formula to make the unknown length the subject.