The perimeter of a rectangle is 48 in. If the length is twice the width, what is the length of the rectangle?

Step one: We need to find the formula for perimeter. And we can't just say "count all the sides". How can we express it? It's length + length + width + width, right? Let's size that down a little bit. 2*length 2*width. We'll use w to express "width" and 2w to express "length".

2 (w) + 2 (2w) = 48.

6w=48.

w=8.

Since length is twice the width, 8*2 is 16. Length=16.

You can check it by substituting the different values for length and width into the equation 2w+2l=perimeter.

2 (8) + 2 (16) = 48. Is this true? Yep! So you know you're right.