A tunnel through a mountain is shaped like a semi-circle. It is 40 feet wide across the bottom. Exactly how high is this tunnel at the points which are 8 feet from the sides.

Answer 1

Draw and label a diagram!

Consider the center of the semi-circle to be at (0, 0)

√(x² + y²) = 20

Now substitute 12 (20 - 8) for x and determine y and answer.