A drawbridge will sometimes open up to let boats and other water traffic pass
through. As it opens, the surface of the drawbridge raises above the level of
the roadway, as modeled by the function:
If the length of the drawbridge, r, is 20 meters, and the point Pis 16 meters
above the roadway, what is the distance d?
O A. 25 meters
O
B. 12 meters
O
C. 19.6 meters
O
D. 36.6 meters

B. 12 meters

Explanation:

The model forms a right angle triangle with the model given as

r = √h² + d²

From the question we were asked to find d when r = 20 meters and the h = 16 meters.

Make d the subject of the formula

r = √h² + d²

square both sides

r² = h² + d²

d² = r² - h²

where

r = 20 m

h = 16 m

d² = r² - h²

d² = 20² - 16²

d² = 400  - 256

d² = 144

square root both sides

d = √144

d = 12 meters