Chapter 6 - Factoring, Solving Equations, and Problem Solving - 6.1 - Factoring by Using the Distributive Property - Problem Set 6.1 - Page 243: 90

The answer is below.

We are told: $A_{parr.} = 2 A_{rect.}$ Using the equation for the area of each and calling the length of the side that has the same measure for each s, we obtain: $ s^2 = 20s \\ s=20 $ Thus: $A_{parr.} = 10(10) = 100 \\ A_{rect.} = 10(20) = 200$