In a rectangular coordinate system, what is the area of a rectangle whose vertices have the coordinates (-8, 1), (1, 1), (1, -7 and (-8, -7)?  Choices
A) 144 B) 36 C) 72 D) 56 E) 112

Rationale: "length of side 1 = 8 + 1 = 9 length of side 2 = 7 + 1 = 8 area of rectangle = 9 * 8 = 72 c is the answer"
Answer: C