The sum of interior angle of a regular polygon is 1980. Find its angle.

The sum of the angles of any polygon with 'n' sides is (n - 2) times 180 degrees.

1980 / 180 = 11, so the polygon has 13 sides and 13 angles.

If the polygon is regular, then all the angles are equal.

Each interior angle is 1980/13 = 152.308 degrees (rounded)