Question

Find the lateral area of the cone in terms of π.

15π cm2


18π cm2


21π cm2


12π cm2

Answer 1

`\textit{lateral area of a cone}\\\\ LA=\pi r√(r^2+h^2)~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ h=4\\ r=3 \end{cases}\implies LA=\pi (3)√(3^2 + 4^2) \\\\\\ LA=3\pi√(9+16)\implies LA=3\pi √(25)\implies LA=3\pi (5)\implies LA=15\pi~cm^2`