# How to Do Math Area Formulas

For each math area formulas I have given a working example with answers, and as always some questions to try.

Math Area Formulas:

Square

Area = Length × Length

or using shorthand (because sometimes Mathematicians are just lazy)

A=L×L

Example 1: Find the area of a square, when the length is 4cm

Area = Length × Length or A=L×L

Area = 4 × 4

= 16cm2

Questions to try:

A) Find the area of these squares with the following lengths,

2. 9cm

(Answers are at the bottom as usual)

Rectangle

Area = Height × Base

or

A=H×B

Sometimes, you may see the math area formulas written as Length × Width. It all depends what you want to call the sides of your shape.

It does not matter what you call them. What matters is that you understand you are multiplying one side of the rectangle by the other side.

Example 2: Find the area of a rectangle, when the height is 3cm and base is 7cm.

Area = Height × Base or using shorthand letters A=H×B

Area = 3 × 7

= 21cm2

Questions to try:

B) Find the area of these rectangles when,

1. H=4m, B=6m

2. H=2km, B=8km

3. H=5cm, B=10cm

Triangle

Area=12×Base×Height

or

1⁄2×B×H

Example 3: Find the area of a triangle, when the height is 5cm and base is 7cm.

Area = 12×Base×Height or using shorthand letters only A= 12×B×H

Area = 12×7× 5

= 17.5cm2

C) Find the area of these triangles when,

1. H=6mm, B=3mm

2. H=4km, B=5km

3. H=100cm, B=3cm

Circle

or writing it shorthand is

A=Π×r2

Example 4: Find the area of a circle when the radius is 4cm.

A=Π×42=3.14×4×4=50.24cm2

Questions to try:

D) Find the math area formulas of these circles when the radius is,

1. r=7m

2. r=25cm

3. r=3.2mm

Example 5: Find the area of a circle when the diameter is 10cm.

The radius is half of the diameter. Therefore, if the diameter is 10cm the radius is 5cm

A=Ππ×r2

A=Π×52=3.14×5×5=78.5cm2

Questions to try:

E) Find the area of these circles when the diameter is,

1. d=8m

2. d=25cm

3. d=16mm

Trapezium

Area=[(Length of a + Length of b)×Height]/2

or

A=[(a+b)×H]/2

First add the lengths of a and b. Then multiply it with the height. Finally divide it by 2.

Example 6: Find the area of a trapezium when the length of a is 2cm, the length of b is 10cm and the height is 4cm

a=2, b=10, h=4

A=[(a+b)×H]/2

A=[(2+10)×4]/2

=48/2

=24cm2

Questions to try:

F) Find the area of the trapezium (in cm) when,

1. a=4, b=8, h=3

2. a=5, b=10, h=4

3. a=3, b=20, h=5

Parallelogram

Area=Base×Height

or

A=B×H

Example 7: Find the area of a parallelogram when the base is 6cm and the height is 5cm.

A=B×H

A=6×5=30cm2

Questions to try:

G) Find the math area formulas of the paralellogram (in cm) when,

1. B=10, H=6

2. B=8, H=9

3. B=20, H=7

'Like' this site?

A)

1. L=6m, 6×6=36m2 which is 360cm2

2. L=9cm, 9×9=81cm2

3. L=2.5m, 2.5×2.5=6.25m2 which is 625cm2

B)

1. H=4m, L=6m, 4×6=24m2

2. H=2km, L=8km, 2×8=16km2

3. H=5cm, L=10cm, 5×10=50cm2

C)

1. H=6mm, B=3mm, 6×3=18/2= 9mm2

2. H=4km, B=5km, 4×5=20/2= 10km2

3. H=100cm, B=3cm, 100×3=300/2=150cm2

D)

1. r=7m, A=Π×72=3.14×7×7=153.9m2

2. r=25cm, A=Π×252=3.14×25×25=1963.4cm2

3. r=3.2mm, A=Π×3.22=3.14×3.2×3.2=32.16cm2

E)

1. d=8m, A=Π×42=3.14×4×4=50.26m2

2. d=25cm, A=Π×12.52=3.14×12.5×12.5=490.87cm2

3. d=16mm, A=Π×82=3.14×8×8=201.06mm2

F)

1. a=4, b=8, h=3, A=[(4+8)×3]/2=18cm2

2. a=5, b=10, h=4, A=[(5+10)×4]/2=35cm2

3. a=3, b=20, h=5, A=[(3+20)×5]/2=57.5cm2

G)

1. B=10, H=6, A=10×6=60cm2

2. B=8, H=9, A=8×9=72cm2

3. B=20, H=7, A=20×7=140cm2

Return from Math Area Formulas to Math Problem Solving

Return from Math Area Formulas to Math Glossary

Find More Math Information Here

Search our Math Problem Solving Directory Listing. Enter your keyword or service you are looking for in the search box right here below.

Purchase author Rakiya Rahman's book:

"I've been moved up to top set...in just a few weeks!"

Eve
Age 9
England

"You make this fun and easy!"
Nathan
Age 8
England

"I can't believe we are doing high school maths, its so easy!"
Yaseen
Age 8
England

"I am getting much better test marks and I have been moved up a set"
Sumera
Age 13
England

"High school's great, I'm in a good math set and I understand lots of things, thanks to you"

Eleanor Talbot
Age 11
England

"I really like math now, you just make it more friendly and normal"
Jess Johnson
Age 18
England

"Your writing style is great, informative but friendly! My 12 year old son still struggles with basic maths. I can see your website will be a real treasure trove for us :)"
Jackie
New Zealand

"This maths twitter is a Legend!"
Liampayneohyes

"I got an A*"

Munira
Age 14
England

"Thanks for teaching me fractions, You made it so easy kalamuni!"
Abrar Haider
Age 8
England

Good, better best.
Never, ever rest.

For every 50th subscriber we will give away £50 worth of Free Math Online Tuition! For more reasons why you should subscribe...

 Enter your E-mail Address Enter your First Name (optional) Then Don't worry — your e-mail address is totally secure. I promise to use it only to send you Math Problem Solving.

A true story: 'Maths is hard, its boring, hardly anyone likes it, but we still won 1st prize'

Like this website?

Get the Results you Deserve

#### +1 Math Problem Solving

Page    Site

For Updates on Free Online Math Tutoring