The distance between the building and the base of the ladder is 5√3 feet.
Explanation:
Consider a right angle triangle,
- Hypotenuse = Paula leaned a 10 ft ladder against a building.
- Height = the top of the ladder is exactly 5 feet up in the building.
- Base = 'x' ft, distance between the building and the base of the ladder.
From the Pythagorean theorem,
Base, x =

⇒ x =

⇒ x =

⇒ x =

⇒ x = 5√3
The distance between the building and the base of the ladder is 5√3 feet.