Using Pythagoras.
13^2 = 5^2 +x^2 when x is the distance from the door.
169 = 25 + x^2
144 = x^2
x = 12
12 feet
A wheelchair ramp needs to be put in place at the new movie theatre. The door to the theatre is 5 feet off the ground and the ramp will measure 13 feet. How far away from the door will the ramp begin? Round to the nearest tenth if necessary.