Geometry 1.4-1.6

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