an 18 foot leans against a wall. The base of the ladder is 9 feet from the wall on the level ground. How many feet up the wall, to the nearest tenth of a foot, is the top of the ladder

15.6

Step-by-step explanation:

We need to use Pythagorean theorem:

hypotenuse ² = (leg 1) ² + (leg 2) ²

Hypotenuse is 18 ft.

leg 1 = 9 ft.

18² = 9² + (leg2) ²

(leg 2) ² = 243

(leg 2) = + √243 ≈ 15.6 (ft)