Question

Find the circumference of Circle if Diameter = 4 cm.

Answer 1

Hint: To solve this question we need to know the basic definitions and formula related to the circle. As we know Circumference of the circle or perimeter of the circle is the measurement of the boundary of the circle. Whereas the area of the circle defines the region occupied by it. If we open a circle and make a straight line out of it, then its length is the circumference. It is usually measured in units, such as cm or unit m.

Complete step-by-step answer:
Here, we have
Diameter=4 cm
Since the diameter is known to us,
we can calculate the radius of the circle.
Radius = $\dfrac{{{\text{Diameter}}}}{{\text{2}}}$
Radius=2 cm
 

Circumference = ${\text{2}}\pi {\text{r}}$
=2 $\pi $$ \times 2$
= 4${\pi }$ cm
Therefore, Circumference of the circle is 4${\pi }$ cm.

Note: Always remember that if Diameter is asked and Circumference of circle is given, then in that case we simply use-
Diameter = $\dfrac{{{\text{circumference}}}}{\pi }$
So, the diameter of the circle in terms of circumference will be equal to the ratio of the circumference of the circle and pi.