Question

a ladder reaches 12m up to a vertical wall and has a gradient of 4. how far is the bottom of the ladder from the wall

Answer 1

well, x^2 + (4x)^2 = 12^2

Answer 2

oops - I misread the question -- I was thinking the ladder was 12m long.
Since the gradient is 4, the ladder goes 4 times as far up the wall as it reaches away from the wall at the base.

Even easier...