Question

What is the surface area of the rightcone below ?

Answer 1

The expression to calculate the surface area of a right cone is,

`SA=\pi* r^2+\pi rl`

From the figure, r=3 cm and l= 15 cm.

`\begin{gathered} S\mathrm{}A=\pi*3^2+\pi*3*15 \\ =9\pi+45\pi \\ =54\pi unit^2 \end{gathered}`

Thus, the surface area of the right cone is 54 square unit and the correct option is option B.