Mammoth Memory

Area of a sector

Using the same reasoning about radians we can also work out the area of any sector of a circle.


Work out the area of the shaded area

Work out the area of this circles circumference using radians


Area of a whole circle`=pir^2`

                                      `=pitimes13^2` `cm^2`                                            

Logic progresses as follows:

`360^@=pitimes13^2` `cm^2`

`150^@=x` `cm^2` 

`360/150` `=` `(pi13^2)/x`
`x` `=` `(pi13^2times150)/360`
`x` `=` `221.22......`
`x` `~~` `221` `cm^2`



The area of the segment is approximately `221` `cm^2`


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