A rectangle has a a perimeter of 72 ft. The length and width are scaled by a factor 3.5.

What is the perimeter of the resulting rectangle?

If the first rectangle has length, l, and width w then its perimeter is given by the following relation

2l+2w=72 divide by 2 on both sides so that the relation now becomes l+w=36

If l and w are scaled by a factor of 3.5, the new measurements of your resulting rectangle will 3.5l+3.5w-->3.5 (l+w)