How_To_Be_Good_At_Math

ALGEBRA • FORMULAS 309

h

w

The volume is the

amount of space

within a 3D shape

h

Using a formula

We use formulas in maths to

find actual values. We can find

the value of a formula’s subject

if we know the values of the

variables on the other side of

the equals sign.

The area is the

space occupied by

the swimming pool

The length when multiplied

by the width gives us 15.

So, the area of this rectangular

swimming pool is 15 m².

We start by replacing

the letters (A = lw) with

the actual measurements.

So, we have A = 5 × 3.

LENGTH 5 m

WIDTH 3 m

Common formulas

Here are some formulas

you will need to know for

finding the area, perimeter,

and volume of some

common shapes. b b

Area of a

triangle

Area of a

parallelogram

Volume

of a cuboid

l l

Perimeter

of a square = 4l

= ½bh = bh

= lwh

w

l

The perimeter is

the distance around

the outside of a shape

Perimeter of

a rectangle = 2(l + w)

h

308-309_Formulas.indd 309 29/02/2016 16:39