Question

A ladder is leaning on a fence and it reaches up a wall 20 feet high. The fence is 10 feet from the wall and the base of the ladder is 12 feet from the fence. How tall is the fence, in feet?

Answer 1

• 10.9 feet

Explanation:

The wall, fence and ladder form similar right triangles as pictured

Use the ratio of corresponding sides to solve for x, the fence height

• x/12 = 20/(10+12)
• x/12=20/22
• x/12 = 10/11
• x = 12*10/11
• x = 10.9 feet

The fence is 10.9 feet tall