Question

A cable 20 feet long connects the top of a flagpole to a point on the ground that is 16 feet from the base of the pole. How tall is the flagpole?

Answer 1

Question #30604

A cable 20 feet long connects the top of a flagpole to a point on the ground that is 16 feet from the base of the pole. How tall is the flagpole?

Solution. The following figure helps to understand the solution

16

We obtain a right triangle. By the Pythagorean theorem

$$x ^ {2} + 1 6 ^ {2} = 2 0 ^ {2}$$

and so

$$x = \sqrt {2 0 ^ {2} - 1 6 ^ {2}} = 1 2.$$

Answer. 12 feet.