The width of a rectangle is 6 cm less than its length. If the area of the rectangle is 135 square cm, find the dimensions. Then find the perimeter of the rectangle.

2 answers

W = Width

L = Length

A = Area

W = L - 6

A = W * L

135 =( L - 6 ) * L

135 = L ^ 2 - 6 L

The exact solution are :

L = - 9 cm

and

L = 15 cm

The length can't be negative so:

L = 15 cm

W = L - 6

W = 15 - 6 = 9 cm

A = W * L = 15 * 9 = 135 cm ^ 2

P. S.

If you don't know how to solve equation:

135 = L ^ 2 - 6 L

Go on:

wolframalpha dot com

When page be open in rectangle type:

solve 135 = L ^ 2 - 6 L

and click option =

After few seconds when you see result click option:

Show steps
perimeter of a rectangle with length 6.6m and width 4.5