Use popsicle sticks to teach children geometric shapes.
To teach equilateral polygons, form shapes from craft sticks.
Later, you can extend the activity using the four craft sticks of the square to discuss the square as a subset of the shapes parallelograms (opposite sides are parallel), rhombuses (opposite sides are parallel and all sides are equal), and rectangles (opposite sides are parallel, opposite sides are equal, and all angles are right angles). All squares also fit the definition of these three shapes.