Question

Find the total surface area of a right circular cone with radius 6 cm and height 8 cm.

Answer 1

$\text{Radius of base of cone (r)=6 cm}andheight\left(h\right)=8cm\therefore Slantheight\left(l\right)=\sqrt{r^2+h^2}=\sqrt{(6{)}^2+(8{)}^2}=\sqrt{36+64}=\sqrt{100}=10cmNowtotalsurfacearea=\pi r(l+r)=\frac{22}{7}\times 6(10+6)c{m}^2=\frac{22\times 6\times 16}{7}=\frac{2112}{7}cm=301.71c{m}^2$