Perimeter and area of a shape

By Yejin and Amy

P=40cm

A=100cm

To find out the area and perimeter of a square you have to do….

10cm

Area: Length x Width

Perimeter: Length + Width + Length + Width

Eg. P=10+10+10+10=40cm A=10x10=100cm

We did 100cm because we times cm by itself, which makes cm

12cm

To find out how to calculate the area and perimeter of a rectangle you have to do…..P=40cm

A=96cm8cm

Area: Length x Width

Perimeter: Length + Width + Length + Width

Eg. 8+12+8+12=40cm A=8x12=96cm

We did 96cm because we times cm by itself, which makes cm

To find out how to calculate the area and perimeter of an isosceles triangle you have to do…..

10cm

10cmArea: height x breadth divide by 2

Why?

Because there are 2 right angled triangles and each has an area of 25cm

Eg. P= 10+11+11= 32cm A=10x10 divide by 2=50cm

We did 50cm because we times cm by itself, which makes cm

A square number is a number that times it by it self , for example….

8 =8 x8 9 = 9 x 9 10 = 10 x 10 11 = 11 x 11

Pythagoras Theorem

Pythagoras was a famous mathematician. It is called Theorem because it is not 100 percent proved to be right.

To see how to do it click…

Example

Pythagoras Theorem

16cm 4cm

3cm 9cm

25cm

5 cm

Circumference of a circle and area of a circle

To get perimeter (called circumference) of a circle you have to do..

D x pi = Circumference of a circle Pi= 3.142To get area of a circle you have to do….R x pi= area of a circle.R= radiusD= diameter

Circumference of a circle and area of a circle

Circumference of a circle= Dxpi

Area of a circle= r x pi

diameter

radius

WRONG!!!!

Quiz!!!!

What do you have to do to get area?

A: Length x width

B:Width x Width

CORRECT!!!!

Quiz

What are the three first numbers of pi?

A: 3.14

B: 3.24

WRONG!!!

CORRECT!!

Quiz!!

What do you have to do to get the circumference of a circle?

A: Dxpi

B: R xpi

Correct!!

Wrong!!

Last quiz

What do you call the area outside a circle?

A: are of a circle

B: don’t know

C: circumference

D: perimeter of a circle

Correct!!

Wrong!!

Half Right Half Wrong!!

Thank you!!!And WELL DONE!!!