One interior angle of a convex polygon (a convex polygon is a polygon where all anglesare less than 180 degrees) is 120 degrees. All the other angles are 130 degrees. How many sides does the polygon have?
120 + 130 (n-1) = 180 (n-2)
120 + 130n -130 = 180n-360
350 = 50n
n=7
