if you notice the picture below
the hexagonal pyramid, is really just a hexagon at the bottom, 6 sides,
and 6 triangles stacked up to each other at the edges
so.. just get the area of the hexagon and the triangles, and add them up, that'd be the surface area of the pyramid
a triangle's area, you'd know is just 1/2 bh, and you have both of those there
now, for the hexagon, notice, we're given the length from the center to one of the sides, namely the "apothem"
thus [tex]\bf \textit{area of a regular polygon}\\\\
A=\cfrac{1}{2}\cdot an\cdot s\qquad
\begin{cases}
a=apothem\\
n=\textit{number of sides}\\
s=\textit{length of one side}\\
----------\\
n=6\\
s=22\\
a=11\sqrt{3}
\end{cases}[/tex]
