Question

What is the sum of the interior angle Measures of an 11 - gin

Answer 1

$\bf \textit{sum of all interior angles in a polygon}\\\\ S=180(n-2)\quad \begin{cases} n=\textit{number of sides}\\ ----------\\ n=\stackrel{11-gon}{11} \end{cases}\implies S=180(11-2)$

and surely you know how much that is.