Question 677294
I = (180(n-2))/n


18 = (180(n-2))/n


18n = 180(n-2)


18n = 180n-360


18n - 180n = -360


-162n = -360


n = -360/(-162)


n = 2.22222222222222



Since the answer is a decimal number, when it *should* be a whole number, this means that it is impossible to have a regular polygon with an interior angle measure of 18 degrees.