A 34-ft. ladder resting against the wall of a building forms a right triangle with the wall and ground. So this is one of the legs and equal 34 feet.
The bottom of the ladder is 8 ft. away from the base of the building. This is another leg and equal 8 feet.
You need to find the hypotenuse.
Using The Pythagorean Theorem:
c^2 = a^2 + b^2, where a and b are legs and c is hypotenuse
c^2 = 34^2 + 8^2
c^2 = 1156 + 64
c^2 = 1220
c = √1220
c = 34.93
Answer
The side of the building = 34.93 ft