Question

A ladder is leaning against a brick wall so that the top of the ladder is even with the top of the wall. If you know that the height of the wall is 20 ft and the distance from the bottom of the ladder to the bottom of the wall is 16 ft less than the length of the ladder, how long is the ladder?

Answer 1

• 20.5 ft

Explanation:

The top of the wall, the bottom of the wall and the bottom of the ladder form a right triangle if connected together.

Let the length of the ladder be x, then as per Pythagorean theorem we have:

• x² = 20² + (x - 16)²
• x² = 400 + x² - 32x + 256
• 32x = 656
• x = 656/32
• x = 20.5 ft

The ladder is 20.5 ft long