Sorry

This answer is incorrect.

The easiest way to do this problem is to look at the rectangular solid all opened up and layed out flat, as shown in the figure below.

If you are having a hard time seeing the box, the sides are all color coded.

• Blue the bottom and the top of the box measuring 6cm x 5cm
• Purple the sides of the box measuring 4cm x 6cm
• Red the ends of the box measuring 4cm x 5cm

In this diagram the shapes that are the same size are in the same color.

Notice that there are two of each shape which is the same size.

A good formula to use to find the surface area would be:

SA = 2(l x h) + 2(l x w) + 2(w x h)

Where SA = surface area, l = length, h = height, and w = width (sometimes called depth)

In this case you would simply substitute into the formula

SA = 2(6 x 4) + 2(6 x 5) + 2(5 x 4) = 148 square centimeters

Now let us try another one

Jeannie has to wrap a box that measures 5 feet on each edge. About how much wrapping paper will she need?

• 100 square feet
• 125 square feet
• 150 square feet
• 200 square feet

Web Related: David.Mazza@grc.nasa.gov
Technology Related: Thomas.J.Benson@grc.nasa.gov
Responsible NASA Official: Theresa M. Scott (Acting)