Question

Each interior angle of the regular n-gon has a measure of 140

Answer 1

Sum of internal angles of any polygon is: (n-2)x180
So measure of an interior edge is ( ( n - 2 ) x 180 ) / n = 140
So 140n = 180n - 360
40n = 360
n = 9
So it's a nonagon.

Hope this helps :)