Solution: Let the number of sides be n and the degree of this inner angle be x. 。

180(n-2)-x= 1650

x= 180(n-2)- 1650

x= 180n-20 10

0 & ltx & lt 180

0 & lt 180n-20 10 & lt； 180

67/6 & lt； n & lt73/6

n= 12

The internal angle is 150 degrees.