Page 355 - Math Smart - 7

CHAPTER 15.4

In this chapter
Surface Area of Cubes Pupils should be able to:

• calculate the surface
area of cubes and
and Cuboids cuboids from their nets

^ RECALL
Investigate!

Look at the net below.
Pizza boxes are made by folding the net of
a box. The surface area of the pizza box Is
the sum of the areas of all the faces of the
box.

Flatten a pizza box. Use a measuring tape
to measure the dimensions of the box
a) What are the
so as to calculate the surface area of the
common shapes of all
flattened box.
its faces?
b) What type of solid
The surface area of a cuboid is the total area of all the faces of the cuboid. has a net like this?
We can use a net to calculate the surface area of a cuboid.

/ X W IXw

/ X h ixh
Solid

Net of solid

All cuboids have six rectangular or square faces. To find the surface area of a
cuboid, we add the areas of the six faces.
Area of each face:
yellow face = l x h
• red face = hx w
^ green face = / x w
There are two of each type of faces in the cuboid.