Question

Area of the circle is 716 cm2

.find it’s circumference.​

Answer 1

Given :

• Area of the circle = 716 cm²

To find :

• Circumference of the circle

Concept :

To find the circumference of the circle, firstly calculate the radius of the circle by using the formula of area of circle. And after getting the value of radius of the circle, substitute it in the formula of circumference of circle to get the required answer.

–↠ Formula of area of the circle :-

• Area of circle = πr²

–↠ Formula of circumference of the circle :-

• Circumference of circle = 2πr

where,

• Take π = 22/7

• r denotes the radius of the circle.

Solution :

Calculating the radius of the circle :-

➪ Area of circle = πr²

Substituting the given values,

➪ 716 = 22/7 × r²

Transposing 22/7 to the left hand side. On transposing, the denominator will become numerator and the numerator will change into denominator.

➪ 716 × 7/22 = r²

➪ 358 × 7/11 = r²

➪ 2506/11 = r²

➪ 227.82 = r²

Taking square root on both the sides.

➪ √227.82 = r

➪ √(15.09 × 15.09) = r

➪ ± 15.09 = r

As we know, the radius of the circle cannot be negative. So, the negative sign will get rejected.

➪ ± 15.09 Reject - ve = r

➪ 15.09 = r

• Radius of the circle = 15.09 cm

Now, calculating the circumference of the circle :-

➪ Circumference of circle = 2πr

➪ Circumference of circle = 2 × 22/7 × 15.09

➪ Circumference of circle = 44/7 × 15.09

➪ Circumference of circle = 663.96/7

➪ Circumference of circle = 94.85

Therefore,

• The circumference of circle = 94.85 cm