| A | B | 
|---|
| a line dividing a shape into two matching halves | line of symmetry | 
| a six-sided figure | hexagon | 
| a polygon with all sides and angles congruent | regular ploygon | 
| a quadrilateral with opposite sides parallel | parallelogram | 
| a simple closed figure fromed by three or more sides | polygon | 
| a ruler or any object with a straight side | staightedge | 
| the point where two edges of a polygon intersect | vertex | 
| the most common unit of measure for an angle | degree | 
| an angle whose measure is between 0 and 90 degrees | acute angle | 
| an angle whose measure is between 90 and 180 degrees | obtuse angle |