What is the length and the width of the rectangle?

A rectangle has a perimeter of 102 cm and the given area (378 cm). Its length is 6 more than four times its width. What is the length and what is the width of the rectangle?

1 Answer
Dec 7, 2017

The width is 9 cm

Explanation:

If the width is w, then the length is 4w+6 and the perimeter is:

102 = 2w+2(4w+6) = 10w+12

Subtracting 12 from both ends, we find:

10w = 90

Dividing both sides by 10, we get:

w = 9

Then the length is 4w+6 = 4(color(blue)(9))+6 = 36+6 = 42

and the area is w(4w+6) = color(blue)(9) * color(blue)(42) = 378 square centimetres - as expected.