triangle
a three sided polygon
Quadrilateral
a four sided polygon
Pentagon
a five sided polygon
hexagon
a six sided polygon
heptagon
a seven sided polygon
octogon
a eight sided polygon
nonagon
a nine sided polygon
decagon
a ten sided polygon
dodecagon
a twelve sided polygon
concave
A polygon that has at least one interior angle more than 180 degrees.
convex
polygon that has all its interior angles less than 180 degrees
complimentary angle
an angle that is 90 degrees
Supplementary angle
an angle that is 180 degrees
adjacent angle
two angles that share a common vertex and a side
linear pair
two adjacent angles, when they have noncommon sides which are opposite rays
vertical angles
when an angle's side form two pairs of opposite rays