Question

Find the circumference of the circle whose area is 38.5 m².

Answer 1

The circumference of the circle is 22m
first find radius of the circle by area of circle formulae
then apply that number in circumference formulae
you will get your answer

Answer 2

Solution :

Let radius of the circle = r m

Area of the Circle ( A ) = 38.5 m²

⇒ πr² = 38.5 m²

⇒ ( 22/7 ) r² = 38.5 m²

⇒ r² = ( 7 × 385 )/( 10 × 22 )

⇒ r² = ( 7 × 7 × 5 × 11 )/( 2 × 5 × 2 × 11 )

After cancellation , we get

⇒ r² =  7²/2²

⇒ r = 7/2 m

∴ Circumference of the circle ( C ) = 2πr

C = 2 × ( 22/7 ) × ( 7/2 )

 = 22 m

∴ Circumference of the Circle = 22 m

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