Rectangle has 4 sides
You have the 2 side lengths (l) and the 2 side widths (w)
"The length is 20 centimeters more than triple the width" in math terms is
l = 20 + 3w
The perimeter is 96 centimeters, which is all the sides added up
2l + 2w = 96
2(20 + 3w) + 2w = 96
40 + 6w + 2w = 96
40 + 8w = 96
8w = 56
w = 7
now plug in w = 7 to get length in
l = 20 + 3w
