## net cubes

A net is a two-dimensional shape that can be folded into a three-dimensional figure.

The net below folds into a cube.

The dimensions of the three-dimensional figure can be used to label the net. Using the dimensions from the rectangular prism, the measures of x, y, and z in the net can be determined.

What are the measures of x, y, and z in the net?

## calculating surface area

The surface area of a prism is the sum of the areas of its faces. Surface area is measured in square units. Use the dimensions of each rectangle in the net to find the area of the faces and base.

Recall that the area of a rectangle is found by multiplying the length by the width. Therefore, you can find the surface area of the rectangular prism with the following calculations.

Surface Area = left side + right side + top + bottom + front + back

S = (5)(3) + (5)(3) + (9)(5) + (9)(5) + (9)(3) + (9)(3)

S = 15 + 15 + 45 + 45 + 27+ 27

S = 174 mm2

Since a rectangular prism has three sets of congruent faces, you can also use a formula to find its surface area. rectangular prism