Question

Find the circumference of a circle of radius $ 175cm $ . ( Take $ \pi = \dfrac{{22}}{7} $ )

Answer 1

Hint: As we know that the circumference of a circle is the perimeter of a circle. It means that the circumference will be the arc length of the circle, as it was opened up and straightened out to make a line segment. We can say that the perimeter is generally the curve length around any closed figure. We can calculate the circumference of the circle by using the formula which is Circumference $ = 2\pi r $ where $ r $ represents the radius of the circle and $ \pi $ represents a constant, which is approximately equal to the ratio of the circumference of any circle to its diameter, here the value $ \pi $ is $ \dfrac{{22}}{7} $ .

Complete step-by-step answer:
As per the given question we have radius is $ 175cm $ and we have to find the circumference of the circle. Now by substituting the values we get Circumference i.e.
 $ C = 2 \times \pi \times r \\
\Rightarrow C = 2 \times 175 \times \dfrac{{22}}{7} $ .
Therefore we get the value $ 1100cm $ .
Hence the circumference of the circle will be $ 1100\;cm $ .
So, the correct answer is “ $ 1100\;cm $ ”.

Note: Before solving such kind of questions we should remember the definitions and formulas for calculating the circumference of a circle. If instead of radius, the diameter is given i.e. the radius of circle is given in the terms of diameter then we should convert into radius by using the formula which is $ R = \dfrac{D}{2} $ , where $ D $ represents the diameter of the circle. Also we can calculate the circumference of the circle directly by the formula $ C = \pi \times d,d $ is the diameter. We should avoid unnecessary mistakes by doing the calculations partly.