Geometric Surfaces
Terms
Altitude of a Cone
-
The segment with one endpoint at the vertex
of a cone and the other in the plane that
contains the base of the cone.
Altitude of a Pyramid
-
The segment with one endpoint at the vertex
of a pyramid and the other at the center of the base of the
pyramid.
Base of a Cone
-
The simple closed curve that bounds part of the
cone.
Base of a Cylinder
-
One of two simple closed curves that lie in
parallel
planes.
Base of a Prism
-
One of two polygons that lie in parallel
planes.
Base of a Pyramid
-
A polygon that bounds part of the pyramid.
Center of a Sphere
-
The fixed point in the interior of a
sphere from which all points on the sphere are
equidistant
Circular Cone
-
A cone whose base is a circle
Circular Cylinder
-
A cylinder whose base is a circle.
Concave Simple Closed Surface
-
A simple closed surface in which one or more
segments* drawn between
points on the surface lie partially or
wholly outside the surface.
Concentric Spheres
-
Spheres that share a common center.
Cone
-
A surface that includes a simple closed curve
and the segments that join all the points on
that curve with a single fixed point not in the
plane of the curve.
Convex Simple Closed Surface
-
A simple closed curve in which a
segment joining any two points on the surface
lies entirely in the interior of the surface.
Cube
-
A regular polyhedron with six faces, all of which are
congruent squares.
Cylinder
-
A geometric surface composed of two congruent simple closed
curves lying in parallel
planes and segments of parallel
lines joining the curves.
Dodecahedron
-
A twelve-faced regular polyhedron whose faces are all congruent
regular pentagons.
Edge
-
The intersection of two polygons in a
polyhedron.
Face
-
A polygon in a polyhedron.
Geometric Solid
-
A region in space bounded by a
closed
surface.
Hemisphere
-
Exactly half of a sphere.
Isocahedron
-
A twenty-faced regular polyhedron whose faces are all congruent
triangles.
Lateral Edge
-
An edge of a polyhedron, usually refers to a prism or a pyramid.
Lateral Face of a Prism
-
The parallelograms of a prism whose edges are
the segments that connect the bases.
Lateral Face of a Pyramid
-
The triangles of a pyramid.
Lateral Surface of a Cone
-
The set of segments that join the base of
a cone with its vertex.
Lateral Surface of a Cylinder
-
The set of segments that join the
bases of a cylinder.
Octahedron
-
An eight-faced regular polyhedron whose faces are all congruent
triangles.
Polyhedron
-
A simple closed surface composed of regions of intersecting
planes--these regions are
polygons
Prism
-
A polyhedron composed of two congruent polygons
that lie in parallel planes and the
segments that are part of parallel lines that
join the congruent polygons.
Pyramid
-
A polyhedron composed of a polygon and the
segments that join that polygon with a fixed
point not in the plane of the polygon.
Radius of a Sphere
-
A segment with one endpoint at the center of
a sphere and the other endpoint on the sphere.
Regular Polyhedron
-
A polyhedron whose faces are congruent regular
polygons
Regular Pyramid
-
A pyramid whose base is a regular polygon
and whose altitude intersects the plane
of its base at the center of the base.
Right Circular Cone
-
A circular cone whose altitude intersects with the
plane of the base at the center of the
base.
Right Circular Cylinder
-
A circular cylinder whose lateral edges are
perpendicular to the
planes that contain the
bases.
Right Prism
-
A prism whose lateral edges are
perpendicular to the
planes of the bases.
Simple Closed Surface
-
A surface that divides space into three
distinct regions: 1) points in the interior of the surface, which always form
the endpoints of finite segments; 2) points
on the surface; and 3) points in the exterior of the surface, which can form the
endpoints of infinite segments.
Sphere
-
A surface whose points all lie an equal
distance from a fixed point in space.
Surface
-
A geometric figure that traces the motion of a
curve in space. A surface is two-dimensional, but can span three dimensions.
Tetrahedron
-
A four-faced regular polyhedron whose faces are all congruent triangles.
Vertex of a Cone
-
The fixed point that is the endpoint of all
the segments that form the lateral surface of a cone.
Vertex of a Polyhedron
-
Any point on a polyhedron that is the intersection of three or more
faces.
Vertex of a Pyramid
-
The fixed point at the intersection of all the
faces of the pyramid.
