Express the perimeter P of a rectangle as a function of the length L. if the width of the rectangle is twice its length.

Question

College Algebra. Not sure how to answer this question. The box to fill in the answer looks like P( ) =

Answer 1

The perimeter (P) of any rectangle can be represented in terms of length (L) and width (W) with the equation P=2L+2W. If the width of the rectangle is twice it's length, then we know that W=2L. By substituting 2L in for W in the perimeter equation we get P=2L+2(2L)=2L+4L=6L, or if we want to represent perimeter as a function of length we get P(L)=6L.

Hope this helps,

Garrett