the diameter of the base of the cone is 6 units, thus the radius of it is 3 then.
[tex]\bf \textit{lateral area of a cone}\\\\
LA=\pi r\sqrt{r^2+h^2}~~
\begin{cases}
r=3\\
h=5
\end{cases}\implies LA=\pi (3)\sqrt{3^2+5^2}
\\\\\\
LA=3\pi \sqrt{34}[/tex]
