What is Shape?
A '''shape''' is a [[geometry|geometric]] [[wikt:figure|figure]] that can be made with [[mathematics]]. Shapes are sorted into kinds based on how the shape looks, and what the shape is made of. For example, shapes can be classified by how many [[dimension]]s they use. [[Two-dimensional]] shapes will fit into a flat [[Plane (mathematics)|plane]]. [[Three-dimensional]] objects will not fit inside a plane, because they are not flat. Shapes made from other shapes of any dimension are called [[polytope]]s. Two shapes are said to be equal, if one can be changed into the other by [[rotation|turning]], moving, growing, shrinking, or more than one of these at once. Geometry is a section of mathematics which involves many shapes and sizes of different figures and their properties. == 2D shapes == These are [[2D|two-dimension]]al shapes or flat [[Plane (mathematics)|plane]] geometry shapes. Their [[side]]s are made of straight or curved lines. They can have any [[number]] of [[side]]s. Plane figures made of lines are called [[polygon]]s. Triangles and squares are examples of polygons. *[[polygon]] **[[circle]] **[[triangle]] **[[quadrilateral]] ***[[square (geometry)|square]] ***[[rectangle]] ***[[rhombus]] ***[[trapezoid]] ***[[parallelogram]] **[[pentagon]] **[[heptadecagon]] == 3D shapes == These are [[3D|three-dimension]]al shapes. Their [[side]]s are made of flat or [[curve]]d [[surface]]s. 3D shapes are most often made of polygon faces. These 3D shapes are called [[polyhedra]]. * [[polyhedron]] ** [[sphere]] ** [[ellipsoid]] ** [[torus]] ** [[cone]] ** [[hemisphere]] ** [[pyramid (geometry)|pyramid]] ** [[tetrahedron]] ** [[cube]] ** [[cuboid]] ** [[parallelepiped]] ** [[rhombohedron]] ** [[octahedron]] ** [[dodecahedron]] ** [[icosahedron]] ** [[cylinder]] ** [[bipyramid]] ** [[frustum]] ** [[Prism (geometry)|prism]] ** [[antiprism]] == 4D shapes == [[4D|Four-dimensional]] shapes made of polyhedra are called [[Polychoron|polychorons]]. These shapes cannot be fully shown in the real world, but they are import