Examine the rectangle below.  

1. What is the perimeter in terms of $x$? In other words, find the perimeter.

   Hint (a):

   The perimeter is all of the sides added together, or $2l+2w$.

2. If the perimeter is $78$ cm, find the dimensions of the rectangle. Show all your work.

   Step (b):

   $\begin{array} 6x+6=78\\ \quad \; 6x=72 \end{array}$
   Solve for $x$ and then substitute for the $x$ in the expressions for the length and the width.

3. Verify that the area of this rectangle is $360$ sq. cm. Explain how you know this.