The length of a rectangle is 3 inches more than its width. If the perimeter is 42 inches, find the dimensions of the rectangle

Question

Must show your work on problem

Answer 1

The problem uses the perimeter formula.  P = 2w + 2l   where w is the width, and l is the length.

 

We know the length (l) is 3 inches longer than it's width (or l = w+3).  Substitute w +3 into Perimeter equation.

 

P = 2w + 2(w+3).  That simplifies to P = 4w + 6.

 

Since P + 42,   we have 42 = 4w +6.  With some simple algebra we find that w = 9 and l = 12.