On graph paper, graph the rectangle with vertices at $(2, 1), (2, 5), (7, 1),$ and $(7, 5)$.   

1. What is the area of this rectangle?

   Answer (a):

   The area is $20$ square units.

2. Shirley was given the following points and asked to calculate the area, but her graph paper is not big enough. Calculate the area of Shirley’s rectangle, and explain to her how she can determine the area without graphing the points.
   
   Shirley’s points: $(352, 150),$ $(352, 175),$ $(456, 150),$ and $(456, 175)$

• Answer (b):

  The area of Shirley's rectangle is $2,600$ square units. To find the length of the two sides, subtract the $x$ and the $y$-coordinates.