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 - L^{2} = 252 or

L^{2} - 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.

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.).