Find the area of a rectangle with a width of 40 cm × cm and a perimeter of 200 cm.

The width of the rectangle is 40 cm.

The perimeter of the rectangle is 200 cm.

Let’s get ahead of the area of this rectangle. We write down the solution.

First, you need to determine the length of this rectangle. We write down the formula.

P = 2 * (a + b).

P = 2a + 2b.

a = (P – 2b) / 2.

a = (200 – 2 * 40) / 2 = (200 – 80) / 2 = 70.

Therefore, the width of the rectangle is 70 centimeters.

Determine the area of this rectangle.

S = a * b = 40 * 70 = 2800 cm ^ 2.

Therefore, the area of this rectangle is 2800 cm ^ 2.

Answer: S = 2800 cm ^ 2.