Question

building is 2 ft fro fence that is 9 ft tall. ladder needs to reach 13 ft from ground. ladder is placed 8 ft from fence. How long is ladder?

Answer 1

So the foot of the ladder is 10 ft from the building.

and you want to reach a height of 13 ft
L^2 = 13^2 + 10^2 = 269
L = √269 = appr 16.4 m

Why do we have to know the fence is 9 ft high?
Am I missing something?