Cool Interior Angle Of A Nonagon References. All sides are the same length (congruent) and all interior angles are the same size (congruent). Irregular nonagon a nonagon in which all sides are not equal and all angles are not equal.
How many angls are in a nonagon? 1 a regular nonagon has nine equal sides and nine equal. The measure of each interior angle of a regular nonagon is equal to 140 degrees.