Question

9. The area of a circle is 497 cm. Its circumference is​

Answer 1

To find the circumference of a circle, we've a direct formula or you can say this shortcut method as well.

The following is the formula to calculate the circumference of a circle if the area is given:

$C = 2\sqrt{A\pi}$

where,

• C - Circumference of a circle.
• A - Area of a circle.
• π - The value of pi is 22/7 or 3.14.

Calculation:

Given that, the area of a circle is 497cm². By substituting the given value in the formula, we get the following results:

$\implies C = 2\sqrt{497\pi}$

$\implies C = 2\sqrt{497 \times \dfrac{22}{7}}$

$\implies C = 2\sqrt{71 \times 22}$

$\implies C = 2\sqrt{1562}$

$\implies C = 2 \times 39.52$

$\implies \boxed{C = 79.04}$

Hence, the circumference of a circle is 79.04cm.

To learn how to find the circumference of a circle if the area is given, refer the link below:

brainly.in/question/48422901

Answer 2

To find : circumference of circle .

Given : area of a circle is $497\ cm$ .

Solution :

• As per the given data we know that area of a circle is $497\ cm$ .We are asked to find circumference of circle .
• Therefore to find circumference of circle we firstly find the radius of circle by using formula of area of circle .
• Area of circle = $\pi r^{2}$

                       $497 =3.14r^{2} \\r^{2} = \frac{497}{3.14} \\r^{2} = 158.280 \\r =12.580\ cm$

• Now , we use following formula to find circumference of circle :

• Circumference of circle $=2\pi r$

                                                $= 2\times 3.14 \times 12.580 \\= 79.0024\ cm$

Hence , circumference of circle is $79.0024\ cm$ .