Circular solids are three-dimensional shapes that have a circular base. Some common synonyms for the term 'circular solids' are cylinders, cones, and spheres. A cylinder is a circular solid that has two circular bases and a curved surface. A cone, on the other hand, has a circular base that tapers to a single point at the top. Lastly, a sphere is a completely round and symmetrical circular solid. Other synonyms for circular solids include hemispheres, tori, and oblates. Each of these shapes has unique properties that make them useful in different applications, from the simple geometry of a cylinder in construction to the perfect symmetry of a sphere in sports such as golf.