Sum of all interior angles of a nonagon is
1260o
1080o
1460o
1620o
Sum of all interior angles of a polygon with n sides = (n - 2) X 180o
Therefore, sum of all interior angles of a nonagon
= (9 - 2) X 180o = 7 X 180o = 1260o
The measure of each interior angle of a regular nonagon is