A right angled triangle of which the sides containing the right angle are 6.3 cm and 10 cm in length,
Question:
A right angled triangle of which the sides containing the right angle are 6.3 cm and 10 cm in length, is made to turn round on the longer side. Find the volume of the solid, thus generated. Also, find its curved surface area.
Solution:
It is given that
Radius of cone(r) = 6.3 cm
Height of the cone (h) = 10 cm
We know that
Slant height $(\mathrm{l})=\mathrm{l}=\sqrt{\mathrm{r}^{2}+\mathrm{h}^{2}}$
$=1=\sqrt{6.3^{2}+10^{2}}=11.819 \mathrm{~cm}$
Therefore volume of cone $(v)=1 / 3 \pi r^{2} h$
$=1 / 3 * 3.14 * 6.3^{2} * 10=415.8 \mathrm{~cm}^{3}$
Curved surface area of cone $=\pi r l$
$=3.14 * 6.3 * 11.819=234.01 \mathrm{~cm}^{2}$