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
