Surface area

1
Surface area
The surface area of a solid is found by adding
the areas of all its faces. To calculate the
surface area you may first sketch the net of the
shape.
2
Example 1
Find the surface area of the following
5m
4m
9m
Left/right 2 4 5 40
Base/top 2 9 4 72
Base/top
Back/front 2 5 9 90
Back/front
SA 40 72 90 202m2
3
Example 2
Find the surface area of the following
x2 52 122 x2 169 x 13
Front 13 7 91
Back 5 7 35
Sides 2 ½ 12 5 60
Base 12 7 84
SA 35 84 91 60 270m2
4
Example 3
Find the surface area of the following
C m
What is the length of the rectangle? The same as
the
circumference of the circle!
Rect LB 2pr h 2 p 5 12 3770
Circles 2 pr2 2 p 52 1571
OR SA 2prh 2pr2 2p5122p52 3770
SA 3770 1571 5341 m2
5
Example 4
Find the surface area of the following
10 m
11 m
12 m
7 m
Base LB 7 12 84
Front/back 2 ½ bh 2 ½ 7 11 77
SA 84 120 77 281 m2
Sides 2 ½ bh 2 ½ 12 10 120
6
Todays work
Exercise 6d page 203 Q1f, Q2e, 3a, 5a, 7bc,
8aeh, 9adef, 10ad, 12