| A | B |
|---|
| equilateral triangle | all sides of this triangle are the same length |
| isosceles triangle | at least two sides of this triangle are the same length |
| scalene triangle | no sides of this triangle are the same length |
| right triangle | this triangle has one right angle |
| acute triangle | this triangle has three acute angles |
| obtuse triangle | this triangle has one obtuse angle |
| rectangle | has four right angles |
| square | four right angles and all sides are the same length |
| trapezoid | only one pair of parallel sides |
| parallelogram | opposite sides are parallel |
| rhombus | opposite sides are parallel and all sides are the same length |
