The surface area of the rectangular solid

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Question from Sara, a student:

For my math homework i found the volume of a rectangular solid whose dimensions were in feet and the numbers were 10 by 20 by 30
10 = height
20 = short side base
30 = long side base
and now i have to find the surface area of the rectangular solid....
i know how to do this but i can't get the right answer
it should be 2,200 ft squared but i keep getting 13,00 feet squared

Hi Sara,

Imagine that your rectangular solid is the inside of a cardboard box. There are 6 pieces of cardboard that make up the box, the top and bottom, the front and back and the 2 sides.

box

Cut the box into the 6 pieces. What are the dimensions of each piece? What is the area of each of the 6 pieces? What is the sum of the areas of the 6 pieces?

Penny

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