# Nouns denoting two and three dimensional shapes

- cardioid
- an epicycloid in which the rolling circle equals the fixed circle
- teardrop
- anything shaped like a falling drop (as a pendant gem on an earring)
- spherical angle
- an angle formed at the intersection of the arcs of two great circles
- cavity
- space that is surrounded by something
- contortion
- a tortuous and twisted shape or position
- shapelessness
- an amorphous or indefinite shape
- base
- the bottom side of a geometric figure from which the altitude can be constructed
- star
- a plane figure with 5 or more points; often used as an emblem
- paraboloid
- a surface having parabolic sections parallel to a single coordinate axis and elliptic sections perpendicular to that axis
- entasis
- a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight
- prismatoid
- a polyhedron whose vertices all lie in one or the other of two parallel planes; the faces that lie in those planes are the bases of the prismatoid
- orbital plane
- (astronomy) the plane on which a body is orbiting
- camber
- a slight convexity (as of the surface of a road)
- pentagon
- a five-sided polygon
- altitude
- the perpendicular distance from the base of a geometric figure to the opposite vertex (or side if parallel)
- hypocycloid
- a line generated by a point on a circle that rolls around inside another circle
- curved shape
- the trace of a point whose direction of motion changes
- Cartesian plane
- a plane in which all points can be described in Cartesian coordinates
- angle of view
- the angle included by a photographic lens
- equator
- a circle dividing a sphere or other surface into two usually equal and symmetrical parts