Answer:
97 ft
Explanation:
The Pythagorean theorem is useful for working problems like this. It tells you the relationship between side lengths and the hypotenuse of a right triangle.
Here, the building is presumed to be perpendicular to the ground, so the 100' rope is the hypotenuse of a triangle with legs equal to 23' and the height of the building (b).
23² +b² = 100²
b = √(10000 -529) ≈ 97.32
The height of the building is about 97 feet.