Question 200217
You just need to find the LCM of 140 & 180. This is 1,260, which when divided by 140 (this being a regular polygon, or a polygon with all equal angles and equal sides), gives us a 9-sided polygon, or a NONAGON.


This sum, 1,260, is also the sum of the angles of all the triangles that make up the polygon, and which when divided by 180 (the sum of all angles of a triangle) equals 7 triangles. Add 2 to this number to get the amount of sides the polygon has, which is 9. 


Hope you understand this!!