Question:
The circumference of a circle exceeds the diameter by 16.8 cm. Find the circumference of the circle.
Solution:
Let the radius of a circle be $r \mathrm{~cm}$, then diameter of circle is $2 r \mathrm{~cm}$ and Circumference is $C=2 \pi r \mathrm{~cm}$.
It is given that the circumference exceeds the diameter of circle by $16.8 \mathrm{~cm}$.
So, circumference $=16.8+$ diameter
$2 \pi r=16.8+2 r \mathrm{~cm}$
$2 \times \frac{22}{7} \times r=16.8+2 r \mathrm{~cm}$
$44 r=117.6+14 r \mathrm{~cm}$
$30 r=117.6 \mathrm{~cm}$
$r=3.92 \mathrm{~cm}$
Now the circumference is
$C=2 \pi r \mathrm{~cm}$
$=2 \times \frac{22}{7} \times 3.92 \mathrm{~cm}$
$=24.64 \mathrm{~cm}$