"In a right-angled triangle the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two"

You have been asked to run a electricity cable from the road to the front door of a house. However the house has a ramp outside the front door.

Note:
The distance from the road to the begining of the ramp = 10 metres
The distance from the begining of the ramp to the wall beneath the front door = 4 metres
The distance from the ground to the bottom of the front door = 3 metres