Two sides of a right triangle have lengths of 2 centimeters and 7 centimeters. The third side is NOT the hypotenuse. How long is the third side?

Use the Pythagorean Theorem: a² + b² = c².

a and b are the leg lengths and c is the hypotenuse.

The hypotenuse is the longest side of the three, so you know the hypotenuse is 7 cm.

We'll make 2 cm = a, and the third side = b.

Plug these into the formula.

2² + b² = 7²

4 + b² = 49

b² = 45

Square root b and 45 to find the length of the third side.

√b = √45

b = 6.71

The third side is 6.71 centimeters.