The interior angles of an octagon add up to 1080 degrees
The interior angles add up to 1800 degrees
The interior angles add up to 12,240 degrees
If it's a regular polygon then each interior angle measures 120 degrees.
No.
Hexagon
2520 degrees
For any polygon of N sides, the sum of the interior angles (in degrees) is 180*N-360, which for N=20 is 3240°
6
The sum of the interior angles of a 12 sided polygon add up to 1800 degrees.
Interior angles total 2520 degrees
3240o
13 of them.