A ladder 16 ft long is leaning against a building. If the base of the ladder is 4 ft from the building, how high up the building will the ladder reach?

Question

A.

12 ft
B.

20 ft
C.

4 square root 15 feet.

D.

4 square root 17 feet.

Answer 1

D. 4 square root 17 feet.

Using the Pythagorean theorem, we can find the height the ladder will reach on the building.

16^2 = 4^2 + h^2
256 = 16 + h^2
240 = h^2
h = √240
h = 4√15

Therefore, the ladder will reach 4 square root 15 feet up the building.