An interior angle is an angle inside a polygon, which is a closed shape with sides and vertices.

In a regular polygon, all interior angles are congruent.

The sum of the interior angles of a polygon of 'n' sides can be calculated using the formula 180(n-2)°.

Each interior angle of a regular polygon of 'n' sides can be calculated using the formula \$((180(n-2))°)/n\$.

Explanation: In the given image, the sum of the interior angles of a polygon is 360°. This can be represented by the formula (n-2)180° where n is the number of sides.

The Exterior Angle is the angle between any side of a shape and a line extended from the next side.

When we add up the Interior Angle and Exterior Angle, we get a straight line of 180°.

These angles are known as Supplementary Angles.

The formula for calculating the measure of an exterior angle of a regular polygon with n sides is \$(360°)/n\$.

Explanation: In the given image, angle b is an exterior angle while angles a and b are interior angles.