PolyhedronA solid formed by polygons that enclose a single region of space

FacesThe flat polygonal surfaces of a polyhedron

EdgeA segment where two faces of a polyhedron intersect

VertexThe point of intersection of three or more edges of the polyhedron

Tetrahedron A polyhedron with four faces

Hexahedron A polyhedron with six faces

Heptahedron A polyhedron with seven faces

Decahedron A polyhedron with ten faces

Dodecahedron A polygon with twelve faces

Regular Polyhedron

A polyhedron with congruent faces that are regular polygons where the faces meet at each vertex in exactly the same way.

PrismA polyhedron with two faces that are congruent, parallel polygons

BasesThe two congruent, parallel faces in a prism

Lateral FacesThe faces of a prism that are not the bases

Lateral Edges The edges where the lateral faces meet

Right PrismA prism whose lateral faces are rectangles

Oblique Prism A prism that is not a right prism

Altitude

Any perpendicular segment from one base to the plane of the other base in a prism or cylinder; the perpendicular segment from the vertex to the plane of the base in a pyramid or cone

Height The length of an altitude

Lateral edge

Pentagonal PrismA prism whose bases are pentagons

Rectangular PrismA prism whose bases are rectangles

Triangular PrismA prism whose bases are triangles

Hexagonal PrismA prism whose bases are hexagons

PyramidA polyhedron with one base and triangular lateral faces

Triangular PyramidA pyramid with a triangular base

Pentagonal PyramidA pyramid with a base that is a pentagon

Trapezoidal PyramidA pyramid with a base that is a trapezoid

Square Pyramid A pyramid with a square base

SphereThe set of all points in space at a given distance from a given point

Radius

The distance from the center of a sphere to the set of points that create the sphere

CenterThe middle point of a sphere

HemisphereHalf a sphere and its circular base

Great CircleThe circle that encloses the base of a hemisphere

Cylinder

A solid with a curved surface formed by two circular bases that are parallel and congruent

AxisThe segment connecting the centers of the bases of a cylinder

Right CylinderA cylinder where the axis is perpendicular to the bases

Oblique CylinderA cylinder where the axis is not perpendicular to the bases

ConeA solid with a curved surface and one circular base

Right ConeA cone with a perpendicular segment connecting the vertex of the cone to the center of the base

Oblique ConeA cone with a segment connecting the vertex of the cone to the center of the base that is not perpendicular