Question

the area of a circle is 38.5 sq cm. what will be its circumference?​

Answer 1

Answer:

The circumference of circle is 22 m.

Step-by-step-explanation:

We have given that,

Area of circle = 38.5 m²

We have to find the circumference of circle.

Let the radius of the circle be r m.

We know that,

Area of circle = πr²

⇒ 38.5 = ( 22 / 7 ) * r²

⇒ r² = 38.5 * 7 / 22

⇒ r = √( 38.5 * 7 ) / √22

⇒ r = √( 269.5 ) / √22

⇒ r = √269.5 / √22 * √22 / √22

⇒ r = √269.5 * √22 / 22

⇒ r = √5929 / 22

⇒ r = √( 121 * 49 ) / 22

⇒ r = √( 11 * 11 * 7 * 7 ) / 22

⇒ r = 11 * 7 / 22

⇒ r = 7 / 2

⇒ r = 3.5 m

∴ Radius of circle = 3.5 m

Now,

Circumference of circle = 2 πr

⇒ Circumference of circle = 2 * ( 22 / 7 ) * 3.5

⇒ Circumference of circle = 2 * 22 * 3.5 / 7

⇒ Circumference of circle = 44 * 0.5

⇒ Circumference of circle = 44 * 1 / 2

⇒ Circumference of circle = 44 / 2

⇒ Circumference of circle = 22 m

∴ The circumference of circle is 22 m.