Question

The angle of a sector of a circle is and the radius of the circle is 21cm. Find the ratio of the circumference of the circle and the length of the area of the sector.

Answer 1

Answer:

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Area is 577.5cm2

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Step-by-step explanation:

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The length of arc l and area A of a sector of angle θ in a circle of radius r is given by,

l =  θ ​ /  360 × 2 π r  

and A =    θ  ​/ 360 × π $r^{2}$   respectively.

Here, r = 21 cm and θ = 150  

  ∴l=  150 / 360   × 2 ×  22 /  7 × 21 = 55 cm

and  

A=  150 / 36   ×   22  / 7 × $21^{2}$  =   1155 / 2  = 577.5 cm2

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