Final answer:
Ellen might have drawn a triangle, which is a three-sided figure with three angles, and a hexagon, a six-sided figure with six angles, given that one figure has three more angles than the other.
Step-by-step explanation:
The question involves Ellen drawing two plane figures with one having three more angles than the other. A shape's number of angles typically corresponds to its number of sides; it's a fundamental property of geometric figures. Considering simple polygons, a triangle is the simplest polygon with the smallest number of angles, which are three. Since one figure has three more angles than the other, if we assume the figure with fewer angles is a triangle, the other figure must have six angles, making it a hexagon. Therefore, Ellen could have drawn a triangle and a hexagon.