How far in feet has each of the midsections been raised?

Question

A drawbridge that is 78 ft in length is raised at its midpoint so that the uppermost points are 6 ft apart.

How far in feet has each of the midsections been raised?

Answer 1

Draw and label a diagram.

The tip of the left side follows the equation x² + y² = 39²

At 6 ft apart the x value is 36 (39 - 3)

36² + y² = 39²

Can you solve for y and answer?