Ahole the size of a photograph is cut from a red piece of paper to use in a picture frame.
what is the area of the piece of red paper after the hole for the photograph has been cut?

By rotating the picture counterclockwise, it is clear that it is a square.

Calculate the length of one side of the picture by using coordinates (1, -3) and (2,1).
a = [(2-1)^2 + (1+3)^2]^0.5 = (1 + 8)^0.5 = 3
The area of the picture is 3^2 = 9.

Calculate the area of the red paper.
Area = 8*8 = 64 

Calculate the area of the red paper after the photograph has been cut.
Area = 64 - 9 = 55

 55