We know that the building must form a right angle with the ground, so the triangle formed by the ladder, the wall, and the distance between the base of the ladder and the wall is a right triangle. We can use the Pythagorean theorem to find the distance the ladder is from the building. a^2 + b^2 = c^2 We know that the ladder is the hypotenuse because it is opposite the right angle. a^2 + b^2 = 20^2 Substitute the length of the other side and solve. a^2 + 17^2 = 20^2 a^2 + 289 = 400 a^2 = 111 The distance from the wall to the bottom of the ladder is the square root of 111 or approximately 10.5357 feet
