Im stuck on that too :/
The interior sum of a 12 sided polygon is 1800.
A 29-sided polygon.
The sum of the interior angles of a polygon with n sides is 180*(n-2) degrees.
The interior angles of a polygon are (number of side -2)*180 = sum of angles
There is no regular polygon with an interior angle of 20o. If the interior angle is 120o then there are six sides and the sum of the angles is 720o.
A Regular Polygon
360 ________________________________________________ Sum of Interior Angles of a Polygon = 180 (n-2) Sum of Exterior Angles of a Polygon = 360 The sum of an angle and an exterior angle of a regular polygon is 360
The sum of each pair of interior and exterior angles of a polygon is always 180 degrees.