Question

What is the circumference of the circle with a radius of 11?

Answer 1

Hint: In the above problem, we have given the radius of a circle and we are asked to find the circumference of the circle. We know that the formula for circumference of the circle is equal to $2\pi r$ where “r” is the radius of the circle so substituting the value of “r” as 11 in this formula then substitute the value of $\pi =\dfrac{22}{7}$ in this equation and solving this equation will give you the value of circumference of circle.

Complete step-by-step answer:
We have given the radius as 11 and we are asked to find the circumference of the circle.
In the below diagram, we have drawn a circle with radius r.

In the above diagram, we have shown radius as AC which is equal to r.
We know that circumference of the circle is equal to:
$2\pi r$
In the above formula, r is the radius of the circle.
Now, substituting the value of “r” as 11 in the above formula for circumference and we get, Circumference of the circle equal to:
$2\pi \left( 11 \right)$………… Eq. (1)
Substituting $\pi =\dfrac{22}{7}$ in the above equation we get,
$2\left( \dfrac{22}{7} \right)\left( 11 \right)$
Multiplying 2 by 22 and by 11 in the numerator of the above expression and we get,
$\dfrac{484}{7}$
Dividing 484 by 7 in the above expression we get,
$67.14$
From the calculations, we have found the circumference of the circle as 67.14.

Note: There is a thought that come to your mind that instead of putting the value of $\pi $ as $\dfrac{22}{7}$ in eq. (1) we can substitute the value of $\pi $ as 3.14. We have shown the equation (1) below:
$2\pi r$
The answer is yes, you surely can put this value of $\pi $ but the point to be noted here is that use that value of $\pi $ which will ease your calculations.