Robert sketches two rectangular prisms, a and b. prism a's side lengths are 5 centimeters, 6 centimeters and 7 centimeters. prism b's side lengths were twice those of prism a's: 10 centimeters,12 centimeters, and 14 centimeters. robert says that surface area of prism b is twice the surface area of prism a. is he correct? if he is not, how many times as great as prism a's surface area is prism b's surface area? show your work.