Question 69

The radii of the two circular faces of the frustum of a cone of height 21 cm are 5 cm and 3 cm. What is its volume in cm$$^3$$($$\pi = \frac{22}{7}$$)

Solution

As per the question,

It is given that, height (h) =21cm, radius (R)=5cm and (r)=3cm

$$\pi = \frac{22}{7}$$

We know that the volume of the frustum of the cone $$V=\dfrac{\pi h(R^2+r^2+R\times r)}{3}$$

$$\Rightarrow V=\dfrac{22 \times 21(5^2+3^2+5\times 3)}{3 \times 7}$$

$$\Rightarrow V=\dfrac{22 \times 21(25+9+15)}{21}$$

$$\Rightarrow V=1078 cm^3$$

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: