Question

Hii✌

The circumference of circle is 42cm.Find the radius of the circle and area of the circle.


Tum log kinna Pgl hona ??? ​

Answer 1

Given :-

• circumferenceof the circle = 42 cm

To Find :-

• radius and area of the circle ?

Solution :-

we know that,

$\boxed{ \bold{circumference \: of \: circle = 2\pi r}}$

$\bold{: \implies 42 = 2 \times \frac{22}{7} \times r} \\ \\ \bold{: \implies r = \frac{ \cancel{42} \times 7}{ \cancel2 \times 22} } \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies r = \frac{21 \times 7}{22} } \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies r = \frac{2247}{22} cm } \: \: \: \: \: \:$

so, the radius of the circle is 2247/22 cm or 102.1363.. cm

now, we know that

$\boxed{ \bold{area \: of \: circle = \pi {r}^{2} }}$

$\bold{: \implies \frac{ \cancel{22}}{ \cancel7} \times \frac { \cancel{2247}}{ \cancel{22}} \times \frac{2247}{ 22} } \\ \\ \bold{: \implies \frac{321 \times 2247}{22} } \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies \frac{721287}{22} {cm}^{2} } \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

hence, the area of the circle is 721287/22 cm² or 32775.7727.. cm²