Let one side be x, the other side is x + 20.
The perimeter of a rectangle = 2(L+W)
Therefore,
180m = 2(x + x + 20)
180m = 2(2x + 20)
180m = 4x + 40
4x + 40 = 180m
4x = 180 - 40
4x = 140
x = 140/4 = 35
One side is 35 so the other side is 55
Let's check our answer
2(35 + 55)
I hope this helps!!
