The length of a rectangle is 5cm more than its width The per

The length of a rectangle is 5cm more than its width. The perimeter is five times the width. What are the dimensions of the rectangle?

Solution

Lets call L to \"lenght\", and W to \"width\".

The formula for the perimeter is: 2W + 2L (2 pieces of fence for each of the leghts, and 2 pieces of fence for each of the widths).

The problem tell us that L = W + 5

The problem also tell us that the perimeter is 5 W

Lets put the data into equations:

1. L = w + 5

2. 2 W + 2 L = 5 W

Replacing the value of L (from the equation 1) in the equation 2:

2. 2 W + 2 L = 5 W

2 W + 2 (W + 5) = 5 W

2 W + 2 W + 10 = 5 W

2 W + 2 W - 5 W = - 10

- W = - 10 (multiplying by - 1)

W = 10

Replacing the value of W in the equation 1:

1. L = W + 5

L = 10 + 5

L = 15

Then, the answer is:

L = 15 cm.

W = 10 cm.