Question

Find the circumference (in cm) of the circle whose diameter is \[5.6m\]

Answer 1

Hint: Firstly convert the unit from meter to centimeter, circumference in another word is also known as perimeter of a circular object. The formula to find the circumference of the circle is:
Circumference of the circle is \[2\pi r\]
where the value of \[\pi =3.14\] (reduced to two places) and \[r\] is the radius of the circle in centimeters.

Complete step-by-step answer:
Now to find the circumference, we first place the value of radius as:
Radius \[=\dfrac{Diameter}{2}\]
Radius \[=\dfrac{5.6\times 100}{2}\] ( \[\times 100\] to convert from meter to centimeter).
\[=\dfrac{560}{2}\text{ }cm\]
\[=280\text{ }cm\]
And for the circumference:
\[=2\pi r\]
\[=2\times 3.14\times 280\]
\[=2\times 3.14\times 280\]
\[=1758\text{ }cm\]

\[\therefore \] The circumference of the circle is \[1758\text{ }cm\].

Note: Another method to find the circumference of the circle in terms of centimeter unit is:
\[=\pi d\times 100\] where \[d\] is the diameter in meters.
\[=\pi \times 5.6\times 100\]
\[=1758\text{ }cm\].