Surface Area

- 3D shapes

The Final Week...

- Today and tomorrow (Mon/Tues) will be dedicated

to finishing surface area and volume. - Wed-Fri will be review days (Finance,

Geometry/Trig and Measurement). - Our exam is WEDNESDAY, JANUARY 25TH, FROM

845AM-1045AM IN THE GYM.

Instructions for use

- There are 9 worked examples shown in this

PowerPoint - A red dot will appear top right of screen to

proceed to the next slide. - Click the navigation bar to the left of screen to

access relevant slides.

3 easy steps to calculate the Surface Area of a

solid figure

- Determine the number of surfaces and the shape

of the surfaces of the solid - Apply the relevant formula for the area of each

surface - Sum the areas of each surface

Surface Area Basic concept

rectangle

rectangle

rectangle

square

square

rectangle

Determine the number and shape of the surfaces

that make up the solid.

When youve done all that find the area of each

face and then find the total of the areas.

It might be easier to think of the net of the

solid.

Square prism

Find the surface area of this figure with square

base 5 cm and ? height 18 cm

Two square faces

Four rectangular faces

18 cm

5 cm

Rectangular prism

Find the surface area of this figure with length

10 cm, width 15 cm and height 12 cm.

20 cm

15 cm

5 cm

Triangular Prism

Find the surface area of this figure with

dimensions as marked.

Square Pyramid

Find the surface area of this figure with square

base 10 cm and ? height 12 cm.

4 triangular faces with the same dimensions and 1

square face

We need to find the ? height of each triangular

face.

12

Rectangular Pyramid

Find the surface area of this figure with

dimensions as marked.

- 5 faces altogether
- 2 pairs of congruent triangular faces
- 1 rectangular face

First find the unknown heights using Pythagoras

theorem

Cylinder

Find the surface area of this cylinder with

height 25 cm and diameter 20 cm.

Think of the net of the cylinder to understand

the formula.

Cone

Find the surface area of this cone of height 15

cm radius 5 cm.

Sphere

Find the surface area of this sphere with

diameter 5 cm.

Required formula

Easy! The sphere is one continuous surface so

just substitute into the formula

Hemisphere

Find the surface area of this hemisphere with

diameter 5 cm.

A hemisphere is a half sphere. But we need

to add in the area of the circular base.

Required formula

Last slide

Use the navigation buttons to repeat selected

slides.