Question:
The circumference of a circle exceeds its diameter by 45 cm. Find the circumference of the circle.
Solution:
Let the radius of the circle be r.
Now,
Circumference = Diameter + 45
$\Rightarrow 2 \pi r=2 r+45$
$\Rightarrow 2 \pi r-2 r=45$
$\Rightarrow 2 r\left(\frac{22}{7}-1\right)=45$
$\Rightarrow 2 r \times \frac{15}{7}=45$
$\Rightarrow r=10.5 \mathrm{~cm}$
∴ Circumference = Diameter + 45 = 2(10.5) + 45 = 66 cm
Hence, the circumference of the circle is 66 cm.