Question

The length of a rectangle is 7 cm longer than 3 times the width. The perimeter is 78. Find the dimensions of the rectangle.

Answer 1

The Length = 31 cm and the width = 8 cm.

Explanation:

L = 3W + 7 where L = the length and W = the width.

2L + 2W = 78.

Substituting for L:

2(3W + 7) + 2W = 78

6W + 14 + 2W = 78

8W = 78 - 14 = 64

W = 64/8 = 8cm.

L = 3W + 7 = 3(8) + 7 = 31 cm.