Question

Find the circumference of a circle whose area is 1386 cm2

Answer 1

Answer:

132 cm

Step-by-step explanation:

first, we have to find out the radius of the circle..

area o the circle = πr²

1386 = 22/7×r²

1386÷22/7÷ = r²

1386×7/22 = r²

√441 = r

21 = r

so, we got the radius 21.

circumference of circle = 2πr

⇒  2×22/7 ×21

⇒2×22×3

⇒44 ×3

⇒132 cm.

Answer 2

Given,

The area of the circle = 1386 cm^2

To find,

The circumference of the circle.

Solution,

We can simply solve this mathematical problem using the following process:

Let us assume that the radius of the circle is x cm.

Mathematically, as per mensuration,

Area of a circle = π×(radius)^2

Circumference of a circle = 2π×(radius){Statement-1}

Now, according to the question)

The area of the circle = 1386 cm^2

=> π×(radius)^2 = π×(x cm)^2 = 1386 cm^2

{according to statement-1}

=> (x cm)^2 = (1386/π) cm^2 = 1386 × 7/22 = 63×7 cm^2

=> x^2 = (3 × 7)^2

=> x = 21 cm

=> radius of the circle = 21 cm

So, the circumference of the circle

= 2π×(radius)

{according to statement-1}

= 2× 22/7 × 21 cm

= (2× 22 × 3) cm

= 132 cm

Hence, the circumference of the circle is equal to 132 cm.