A rectangle has perimeter 20m. Express the area of the rectangle as a function of the length of one of its sides.

Area of rectangle is 10L-L²

Step-by-step explanation:

Let L be the length and W be the width.

Perimeter of rectangle = 2 (L + W)

That is

2 (L + W) = 20

L + W = 10

W = 10 - L

We need to express the area of the rectangle as a function of the length of one of its sides.

Area = Length x Width

A = LW

A = L (10 - L) = 10L-L²

Area of rectangle is 10L-L²