Polygon
A closed figure made of three or more line segments in the same plane
Sides
Each of the line segments that make up a polygon
Vertices
The endpoints of the line segments that make up a polygon that meet
Triangle
A polygon with three sides
Quadrilateral
A polygon made with four sides
Pentagon
A polygon made up of five sides
Hexagon
A polygon made up of seven sides
Regular polygon
A regular polygon is a polygon with all congruent interior angles
Octagon
A polygon with eight sides
Regular octagon
An octagon with all congruent interior angles
Perimeter
The sum of the lengths of all the sides of a polygon
Area
The region enclosed in the sides of a polygon.