Question

Tommy and Cole are planning to build an aquarium for their pet fish. If the dimensions of the aquarium are 17 inches long, 9 inches wide, and 11 inches tall, how much glass do they need to buy to enclose the aquarium?

Answer 1

Surface area of a rectangular box = 2(lw + lh + wh).

Here l = 17, w = 9, h = 11:
lw = 17·9 = 153
lh = 17·11 = 187
wh = 9·11 = 99

Total area = 2(153 + 187 + 99) = 2(439) = 878 square inches.

(About 878 in² ≈ 6.10 ft².)