Which of the following must be shown in order to prove that two irregular polygons are similar

a. the sides need to be proportional
b. corresponding angles are equal
c. both a and b are required
d. neither a or b are correct

Irregular polygons are polygons in which the sides are not equal to each other. This also means that the internal angles are not equal to each other. Similar polygons, on the other hand, are polygons with equal corresponding angles which makes the sides proportional to each other correspondingly. The answer then is C.