| A | B |
|---|
| Triangle | 3 sided polygon |
| Polygon | a closed plane figure whose sides are line segments |
| Quadrilateral | a 4-sided polygon |
| Pentagon | a 5-sided polygon |
| Hexagon | a 6-sided polygon |
| Octagon | an 8-sided polygon |
| Nonagon | a 9-sided polygon |
| Decagon | a 10-sided decagon |
| Dodecagon | a 12-sided decagon |
| Equilateral Triangle | a triangle with all sides congruent |
| Isosceles Triangle | a triangle with at least 2 sides congruent |
| Scalene Triangle | a triangle with no sides congruent |
| Acute Triangle | a triangle with 3 acute angles |
| Obtuse Triangle | a triangle with one obtuse angle |
| Right Triangle | a triangle with one right angle |
| Regular Polygon | a polygon with all sides and angles congruent |
| Diagonal | a line segment that joins to vertices of a polygon but is not a side |
| Parallelogram | a quadrilateral with opposite side parallel and congruent |
| Trapezoid | a quadrilateral with only one pair of parallel sides |
| Rectangle | a parallelogram with four right angles |
| Rhombus | a parallelogram with four congruent sides |
| Square | a rectangle with four congruent sides |
| 180 degrees | the degrees of the interior angles of a triangle |
| interior angles | the angles inside of a polygon |
| exterior angles | the angles outside of a polygon |
| 360 degrees | the degrees of the exterior angles of a triangle |
