GEOmetrY!!!!!!!!!!?

Equiangular is when all the angles of a polygon have the same measure. Regular is when all sides are equal and all angles are equal. concave is when one or more sides of the shape go in towards the center. Convex is when none of the sides go in towards the center. As far as the rule, a parallelogram is anything that has 2 or more parallel sides so a rectangle can be a parallelogram. Never heard of the rule though....