Question

Sally has Christmas lights the roof is 16 feet high the ladder is 20 ft long how far away is letter from wall

Answer 1

It should be 12 ft away from the wall. Not 4 ft. You do not just subtract the difference because as you pull it away from the wall, the ladder is mostly moving horizontally with only a small vertical change.

You can use Pythagorean Theorem to find the answer. Think of the ladder as the hypotenuse of a right triangle with the wall and the ground as the legs.

a^2 + b^2 = c^2

16^2 + b^2 = 20^2

b^2 = 20^2 - 16^2

b^2 = 144

b = 12 ft