Question

The length of a rectangle is 2 km less than 3 times the width. The perimeter is 68 km. How long is the length?

Answer 1

Length = 25 km

Explanation:

Let L = length, W = width

L = 3W - 2

Perimeter of a rectangle given L and W is 2(L + W) and is given as 68

==> 2(L + W) = 68

==> So L + W = 68/2 = 34

Since L = 3W -2

L + W = 3W -2 + W = 4W - 2

L + W = 4W - 2 = 34

Solve 4W - 2 = 34:

4W = 34+ 2 = 36

W = 36/4 = 9

L = 3 x 9- 2 = 25