A 35 foot ladder is leaning against a building. The base of the ladder is 21 feet from the side of the building. How high does the ladder reach along the side of the building?

28 feets

Step-by-step explanation:

Given that:

Height of ladder = 35

Distance between foot of ladder and wall base = 21 feets

The height of the ladder = h

Kindly refer to attachment for diagram illustration :

Using Pythagoras rule :

h² = 35² - 21²

h² = 1225 - 441

h² = 784

h =sqrt(784)

h = 28 feets

Height of ladder along the side of the building = 28 feets