Equal volume solids set, 125cm3.

These things were made with Tinkercad. I wanted a model of why soap bubbles are spherical. (Soap bubbles are spherical in order to maximize the volume of gas trapped while minimizing the surface area of the soap film.) These models show the surface area of different shapes with the same volume. Set contains cube, sphere, cylinder, pyramid, and torus.

Note: the torus is not exactly precise, due to the limitations of the Torus shape in Tinkercad. But it's close enough for this demonstration.