a 70-ft ladder is mounted 10 ft above the ground on a fire truck. The bottom of the ladder is 40 ft from the wall of a building. The top of the ladder is touching the building. High off the ground is the top of the ladder?
if you ignore the ten feet for a moment - because the ten feet has nothing to do with the side of the triangle, you can calculate the length of the ladder vertially, the third side (the length of the wall from bottom to top of ladder) using the pythagorean theorem a^2+b^2=c^2, which is 40^2+b^2=70^2, which gives you a rounded answer of 57.45. Then, since the length from the bottom until the top of the ladder vertically while its on the truck is 57.45, and that's when its 10 feet off the ground, you simply add the 10 to the 57.45 to get 67.45.
