The length of the rectangle is more than 10 cm, and the width is 2.5 times less than the length.

The length of the rectangle is more than 10 cm, and the width is 2.5 times less than the length. Prove that the perimeter of the rectangle is greater than 28 cm.

First, you need to determine the width of the rectangle.

To do this, divide the length by 2.5.

Will be:

10 / 2.5 = 4 cm.

Since the length is more than 10 cm, the width of the rectangle will also be more than 4 cm.

We find the perimeter.

To do this, we add together all the sides of the rectangle.

Will be:

10 + 10 + 4 + 4 = 28 cm.

Since the sides are larger than the indicated values, then their sum will also be more than 28 cm.

If the length is 10.1 cm and the width is 4.1 cm, we get:

2 * (10.1 + 4.1) = 2 * 14.2 = 28.2 cm.

Answer: The perimeter is more than 28 cm.