The interior angles of an 11 sided polygon add up to 1620 degrees
It doesn't matter what shape it is, the sum of the exterior angels in any polygon is 180.
That's the definition of "supplementary angels".
The sum of all the interior angles of any trapezoid is 360 degrees.
The sum of the interior angles of an n-gon is (n-2)*180.
The interior angles of an 11 sided polygon add up to 1620 degrees
The sum of the internal angles is 180*(11 - 2) = 180*9 = 1620 degrees. The sum of the external angles is 360 degrees - irrespective of the number of sides.
16.36* It is, in fact, twice that: 32.7272.. degrees.
Supplementary
It doesn't matter what shape it is, the sum of the exterior angels in any polygon is 180.
180
180 degrees
That's the definition of "supplementary angels".
360 degrees
540 degrees
Yes.
1800 degrees from 12 angels