-- The width of the school is ' W '. We don't know what that is yet,
but we're going to find out.
-- We're told that the length is 4 times as much. So the length is ' 4 W '.
-- Perimeter is (2 widths) + (2 lengths).
2 widths = 2 W
2 lengths = 8 W
Perimeter = 10 W
-- We're also told that the perimeter is 55m. That's just what we need.
10 W = 55 m
Divide each side of this equation by 10:
W = 5.5 m
There's the width !
The length of the hall is 4 times as much.
Length = 4 W = 22 m
