how to find length?

Question

The length of a rectangle is twice the width. The area is 578 sq centimeters. What is the length?

Answer 1

How?  By using ALGEBRA!

1. DRAW THE RECTANGLE.

2. LABEL THE WIDTH w

3. LABEL THE LENGTH 2w.

4.  A = length times width, so w(2w) = 578.

5.  Finish the job!