a right triangle. If AC = 7 and BC = 8, find AB. Leave your answer in simplest radical form.

We don't know whether those two sides are both legs

of the right triangle, or if BC is the hypotenuse.

If AC and BC are both legs, then

AB = √ (AC² + BC²)

= √ (7² + 8²)

= √ (49 + 64) = √ 113.

If BC is the hypotenuse of the right triangle, then

AB = √ (BC² - AC²)

= √ (8² - 7²)

= √ (64 - 49) = √ 15.