| A | B |
|---|
| acute angle | an angle less than 90° |
| acute triangle | a trianle with 3 acute angles |
| congruent sides | sides with the same length |
| equilateral triangle | all sides are the same size |
| hexagon | a 6-sided polygon |
| isosceles triangle | a triangle with at least 2 sides equal |
| kite | a quadrilateral with two pairs of adjacent sides of equal length |
| obtuse angle | an angle larger than 90º but less than 180º |
| obtuse triangle | a triangle with an obtuse angle |
| octagon | an 8-sided polygon |
| parallel lines | lines that stay the same distance apart and never meet or cross |
| parallelogram | a quadrilateral with opposite sides that are the same length and parallel |
| pentagon | a 5-sided polygon |
| perpendicular lines | lines that meet or cross at a 90º angle |
| polygon | a 2-dimensional closed figure with at least 3 straight sides - no curves |
| quadrilateral | a polygon with 4 sides and 4 angles |
| rectangle | a parallelogram with two pairs of congruent, parallel sides and four right angles |
| regular polygon | a polygon in which all sides are the same length and all angles have the same measure |
| rhombus | a parallelogram with all sides the same length |
| right triangle | a triangle with 1 right angle |
| scalene triangle | a triangle in which each side has a different length |
| trapezoid | a quadrilateral with exactly one pair of parallel sides |
| square | a parallelogram with two pairs of congruent, parallel sides, four right angles and all sides the same length |
