What is the minimum interior angle possible for a regular polygon?

For a regular polygon, as the number of sides increase, interior angle also increases and exterior angle decreases. Therefore, a polygon with a minimum interior angle and maximum exterior angle is an equilateral triangle, as it has the minimum number of sides possible for a polygon i.e., 3. (a) The interior angle of an equilateral triangle is 60°, which is the minimum interior angle possible for a regular polygon. (b) The exterior angle of an equilateral triangle is 180° - 60° = 120°, which is the maximum exterior angle possible for a regular polygon.