This is for stability.
Two cylinders with the same volume are not necessarily congruent. One could have a different diameter and length than the other, and still have the same volume.
729:1
6 to 1
There are a number of possible 7-sided polyhedra. Three that come immediately to mind are: a hexagonal pyramid, a pentagonal prism, a "stretched" triangular pyramid (triangular base, rectangular sides, and then triangular faces meeting at an apex).
Cylinders and cones are not considered polyhedrons because they do not have flat faces, which is a defining characteristic of polyhedrons. Polyhedrons are three-dimensional shapes made up of flat surfaces, while cylinders and cones have curved surfaces. Additionally, polyhedrons have straight edges where faces meet, whereas cylinders and cones have curved edges. Therefore, cylinders and cones are classified as curved surfaces rather than polyhedrons.
Polyhedra are 3-dimensional shapes bounded by polygons. Polygons are flat [plane] shapes bounded by straight lines. So a polyhedron cannot have any curved faces.
Strictly speaking, no. But, as the number of faces increases, polyhedra can approximate cylinders or spheres and so can "roll".
False. Cylinders and cones are not just polyhedrons with circular bases.
There is no universal formula for volume: it depends on the shape. There are formulae for the volumes of some shapes such as cuboids (including cubes), cones, ellipsoids (including spheres), regular polyhedra (including pyramids), prisms (including cylinders). But there are many more irregular shapes for which no formulae exist.
Pyramids and cones have a pointed top (apex) while prisms and cylinders have flat tops. Pyramids and cones have a single base, while prisms have two parallel bases. Cones have a curved surface while pyramids have triangular faces.
Cones, cylinders.
polygons have faces and cylinders and cone and spheres only has bases not faces.
Cones, hemispheres, and cylinders have.
A circular cross-section.
Prisms: Feed troughs, bathtubs, and boxes. Pyramids: Pyramids of Egypt and the Aztecs. Cylinders: Cans, pistons, tubes, and pipes. Cones: Ice cream cones, funnels, and the bottom part of a water tower.
polyhedrons need flat face and edges, corners which cylinder cones don't have.