Question

circumference of circle is 31.4cm find the area of the circle ( take pie as 3.14​

Answer 1

Given :-

• Circumference of the circle is 31.4
• π = 3.14

To Find :-

• Area of the circle ?

Solution :-

we know that,

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

$\bold{: \implies 31.4 = 2 \times 3.14 \times r } \\ \\ \bold{: \implies r = \frac{ \cancel{31.4 }}{2 \times \cancel{ 3.14}} } \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies r = \cancel \frac{10}{2} } \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \bold{: \implies r = 5 \: cm} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

so, radius of the circle is 5 cm

now,

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

$\bold{: \implies 3.14 \times 5 \times 5 } \\ \\ \bold{: \implies 78.5 \: {cm}^{2} } \: \: \: \: \: \:$

hence, area of the circle is 78.5 cm²

Answer 2

Answer:

$\huge\underline\mathfrak\red{question}$

=> circumference of circle is 31.4cm. find the area of the circle ( take pie as 3.14)

$\huge\underline\mathfrak{understanding\:the\:question}$

==> in the question it's given that the the circumference of circle is 31.4 cm and we have to find the area of circle. to find area of circle we have to find radius.

so, first we will find radius and then we will find the area of circle.

$\huge\underline\mathfrak\blue{answer}$

=> let's do it !!

• => circumference of circle= 31.4cm

• => pie as 3.14

=> find radius:-

==> 31.4 = 2πr

==> 31.4= 2× 3.14× r

==> 31.4= 6.28× r

==> 31.4÷6.28= r

==> 5 = r

==> radius= 5cm

hence we find the radius is 5cm

now, fine the are of circle:-

$= = > a = \pi \: {r}^{2}$

$= = > 3.14 \times 5 \times 5$

$= = > 3.14 \times 25$

$= = > 78.5cm$

==hence the area of circle is 78.5cm²