Question

Erica wants to decorate a rectangular box by covering all the faces of the box, including the top and bottom, with 1-inch square pieces of paper. If the box has a height of 3 inches, a width of 5 inches and a length of 7 inches, how many squares of paper will she need? Show and explain your work.

Answer 1

142

Explanation:

This is a Total Surface Area problem.

The box has 6 faces (sides): front, back, left, right, top, bottom. They are all rectangles. Area of a rectangle is length × width.

You find the area of each face and add them all up.

see image.

TSA = 15+15+21+21+35+35

= 30+42+70

= 142 sq inches

Erica needs 142 pieces of paper to decorate her box.