Question:
The curved surface area of a cylinder is 1320 cm2 and its base has diameter 21 cm. Find the volume of the cylinder.
Solution:
r cm = Radius of the cylinder
h cm = Height of the cylinder
Diameter of the cylinder is 21 cm. Thus, the radius is 10.5 cm.
Since the curved surface area has been known, we can calculate h by the equation given below:
The curved surface area of the cylinder = 2πrh
1320 cm2= 2πrh
$1320 \mathrm{~cm}^{2}=2 \times \frac{22}{7} \times(10.5 \mathrm{~cm}) \times h$
h = 20 cm
∴ Volume of the cylinder (V) = πr2h
$V=\frac{22}{7}(10.5 \mathrm{~cm})^{2}(20 \mathrm{~cm})$
V = 6930 cm3