Answer:
≈ 14 feet
Explanation:
this situation creates a right triangle with the ladder being the hypotenuse and legs distance from base of ladder and height of ladder (h) up the wall
using Pythagoras' identity in the right triangle.
the square on the hypotenuse is equal to the sum of the squares on the other two sides, that is
h² + 5² = 15²
h² + 25 = 225 ( subtract 25 from both sides )
h² = 200 ( take square root of both sides )
h =
≈ 14 feet ( to the nearest foot )