A cone has a circular base and a single vertex. The volume of a cone is calculated using the formula: Volume = 1/3 * π * r^2 * h, where r is the radius of the base and h is the height. For a conical container filled with 821 1/3 cm^3 of water, the height is calculated to be 7 cm. A conical frustum is formed by slicing off the top of a cone parallel to the base. The volume and surface area of cones and conical frustums can be calculated using various formulas provided in the document.