A blue square is divided into five congruent rectangles. If the perimeter of one rectangle is 36, find the perimeter of the blue square.
+128475
The perimeter of the rectangle =
36 = 2 (W + L)
18 = W + L (1)
And let the side of the square = S ....so.....
10W = 2S ⇒ 5W = S ⇒ S/5 = W (2)
2L = 2S ⇒ L = S ⇒ S = L (3)
Sub (2) and (3) into (1) and we have that
18 = S/5 + S
18 = (6/5)S
18 (5/6) = S
15 = S
So....the perimeter of the square = 4S = 4 (15) = 60
