| A | B |
|---|
| octogon | a polygon with 8 sides |
| rhombus | a quadrilateral whose sides are all the same length |
| right angle | an angle that measures 90 degrees |
| trapezoid | a quadrilateral with exactly one pair of parallel sides |
| square | a rectangle with 4 equal sides and 90 degree angles |
| equilateral triangle | a triangle with all sides the same length |
| perpendicular lines | two lines that intersect on a 90 degree angle |
| parallel lines | lines that never meet and are the same distance apart |
| pentagon | a polygon with 5 sides |
| quadrilateral | a polygon that has 4 sides |
| acute angle | an angle that measures between 0 and 90 degrees |
| hexagon | a polygon with 6 sides |
| isosceles triangle | a triangle with at least two sides of the same length |
| obtuse angle | an angle that measures between 90 and 180 degrees |
| reflex angle | an angle that measure between 180 and 360 degrees |
| straight angle | an angle that measures 180 degrees |
| vertical angles | angles that are opposite each other |
| adjacent angles | angles that are next to each other and share a common side |
| supplementary angles | two angles whose measure totals 180 degrees |
