Finding the surface area of a 3D solid The surface area of a 3D solid is the total area of all the faces on the solid.
There are two methods we can use to fi nd the surface area of a 3D solid.
Worked example 2 Find the surface area of the rectangular cuboid.
8 cm Solution 5 cm 6 cm Side
Top Front
8 cm 8 cm
Base
8 cm 8 cm
Back 5 cm Side 5 cm 6 cm 6 cm 5 cm
Practice questions 17.2
1. Copy these solids. For each solid, identify the following features. (i) A face
(ii) An edge (iii) A vertex
2. Which of the following diagrams could be the net of the cube given? Justify your answer. (Note: A solid can have more than one net. In fact, a cube has 11 unique nets.) A