The length of the rectangle is 7 cm. Find its area if the perimeter is 16 cm?

The expression for calculating the perimeter will be:
P = 2 * (a + b), where P is the perimeter, a is the length, b is the width.
Find the width from this expression:
a + b = P / 2;
b = P / 2 – a.
Substitute the numeric values and define the perimeter of the rectangle:
16/2 – 7 = 1 cm rectangle width.
Now we can find out the area of the rectangle:
7 * 1 = 7 cm2
Answer: 7 cm2 area of a rectangle.