GCSE revision notes

This page goes through the key facts and formulae to know when finding area.

Ensure you can do all of them do not skip an example however trivial it may seem to you. Check carefully THAT YOU WOULD have got the same answer.

The examples progress from simple C grade examples to harder A grade examples.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Composite Shapes

The key is to break it up in to separate shapes

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

Key points:

The formula is given in the examination

are the parallel sides

is the height of the trapezium

 
 


A trapezium:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

Fractions of circles

The 8cm is the diameter.

So the radius is 4cm

The area of the full circle would be:

So the area of the semi-circle is:

 
A semi-circle

 

 

 

 

 

 

 

 

 

 

 

 

 


The radius is 5cm

The angle is

Area

The area of the full circle is

The fraction of the circle is

So the area of the sector is

Perimeter

The circumference of the full circle would be

So the curved length is

So the total perimeter is:

 

 

 

 

 

 

 

 

 

A sector a fraction of a circle