Polyhedra and Non-Polyhedra
polygon
A closed, plane figure formed by three or more line segment
octagon
A eight-sided polygon
pentagon
A five-sided polygon
quadrilateral
A four-sided polygon.
nonagon
A nine-sided polygon
triangle
A polygon with three sides.
heptagon
A seven-sided polygon
hexagon
A six-sided polygon
decagon
A ten-sided polygon
dodecagon
A twelve-sided polygon
regular polygon
a polygon with congruent sides and congruent angles
irregular polygon
a polygon with incongruent sides and incongruent angles
geometric solid
a three-dimensional shape
congruent
equal
face
flat surface on a geometric solid
polyhedron
solid bounded by polygons
non-polyhedron
solid with round surfaces
vertex
the point where two lines (on a polygon) or three faces (on a geometric solid) intersect
edge
the segment where two faces on a geometric solid intersect
perimeter
the sum length around a polygon
net
two-dimensional pattern of a three-dimensional figure; can be folded into a geometric solid
