At the start of the day, a painter rested a
3 m ladder against a vertical wall so that
the foot of the ladder was 50 cm away
from the base of the wall.
During the day, the ladder slipped down
the wall, causing the foot of the ladder to
move 70 cm further away from the base
of the wall.
How far down the wall, in centimetres, did
the ladder slip?
Give your answer to the nearest 1 cm.
