Question

3. The slant height and diameter of base a cone of a cone are 21 cm and 24 cm
respectively. Find the a) Curved surface b) Volume​

Answer 1

Answer:

Curved Surface Area of Cone = $792cm^{2}$

The Volume of Cone = $48\sqrt{297} \pi cm^{3}$

Step-by-step explanation:

The Diameter of Cone$(d)$ = $24$ $cm$

The Radius of Cone$(r)$ = $\frac{d}{2}$ = $12$ $cm$

The Slant Height of Cone$(l)$ = $21$ $cm$

$a)$ Curved Surface Area of Cone = $\pi rl$

⇒$\frac{22}{7} *12*21$

⇒$22*12*3$

⇒$792cm^{2}$

$b)$Height of Cone$(h)$ = $\sqrt{l^{2}-r^{2} }$

⇒$h = \sqrt{441 - 144}$

⇒$h= \sqrt{297}$

The Volume of Cone = $\frac{1}{3} \pi r^{2} h$

⇒$\frac{1}{3} *\frac{22}{7} *144*\sqrt{297}$

⇒$48\sqrt{297} \pi cm^{3}$