Search 70,342 tutors

Ask questions and get free answers from expert tutors

The area of a rectangle is 252 square feet. If the perimeter is 66 feet, find the length and width of a rectangle?

WyzAnt Tutors: Sign In to answer this question.

4 Answers

Hello, Jesse --

You need to use your information about area and perimeter to set up two equations with two variables representing length and width of the rectangle. Then you will set up a quadratic equation. Let's use L for the length and W for the width of the rectangle:

For the perimeter:

          2L + 2W = 66  or  
             L + W  = 33  or
                   W  = 33 - L


For the area:

             LW =  252

Now substitute W = 33 - L from the first equation into the second one:

             L(33 - L) = 252  or

              33L - L2 = 252  or

               L2 - 33L + 252 = 0


This can be solved by factoring, or by using the quadratic equation.

By factoring:

          (L - 12)(L - 21) = 0  or

                  L = 12, or L = 21

In this case, let's use 21 because length is usually the longer dimension. Now we substitute L = 21 into the first equation to find W.

        W = 33 - 21 or
         W = 12

Your answers are:  Length = 21 and Width = 12

 

add comment

A = 252 sq. ft = l*w

2l + 2w = 66, 2(l+w) = 66, so l+w = 33

w = 252/l

l+(252/l) = 33

l^2 + 252 = 33l

l^2 - 33l - 252 = 0

You're at a quadriatic equation, which you can solve. You will get two answers - toss out the unreasonable one (hint - negative answer, won't fit with the width, etc.).

add comment

Algebra 1 Tutors available for hire in your area

WyzAnt Tutoring

  • Jennifer A.
    Excellent Math Tutor
    New York, NY
     
    102 ratings
    24 subjects including
    Algebra 1
  • Sam E.
    Math and Writing Tutor, NYC Ivy League Graduate
    New York, NY
     
    7 ratings
    42 subjects including
    Algebra 1
  • Makunda M.
    Enhanced Tutoring
    Brooklyn, NY
     
    58 ratings
    15 subjects including
    Algebra 1
Find more Algebra 1 Tutors »

Please sign in to comment.