The foot of a ladder is 6 m from the base of an electric pole. The top of the ladder rests against the pole at a point 8 m above the ground. How long is the ladder?
Worked solution (try it first)
The ground, the pole and the ladder make a right-angled triangle with the ladder as the hypotenuse.
Pythagoras: the ladder is 62+82=100=10 m, option C.