Problem solving

Question

A rectangle has a length that is three times as long as the width. Riley says the perimeter of the rectangle can be written as 6w. Is this correct? Explain.

Answer 1

Let w = width

Then 3w = length

Perimeter = 2w+2l

P = 2w+2(3w)

P=2w+6w

P=8w

The answer they gave was not correct. They only accounted for the lengths, not the widths.