Question 11

Find the volume of a cylinder whose radius is one-third the radius of a circle of area 1386 $$cm^2$$, and height is twice its radius.

Solution

Area of the circle = $$\pi\times r^2$$

1386 $$cm^2$$= $$\pi\times r^2$$

r = 21 cm

cyclinder

R = $$\frac{1}{3}r$$

H = 2r

area of cyclinder = $$\pi\times r^2\times h$$

$$\pi\times (\frac{1}{3}r)^2\times 2r$$

$$\pi\times (\frac{1}{3}21)^2\times 2\times 21$$

=2156 $$cm^3$$

Create a FREE account and get: