| A | B |
|---|
| Scalene Triangle | A triangle with all sides of different lengths. |
| Obtuse Triangle | A triangle with one obtuse angle. |
| Right Triangle | A triangle with one right angle. |
| Equilateral Triangle | A triangle with all three sides of the same length. |
| Equiangular Triangle | A triangle with all three angles of the same length. |
| Isoceles Triangle | A triangle with two sides the same length. |
| SAS Postulate | Proves two triangles are congruent with two sets of sides and the included angle congruent. |
| Perpendicular lines | Two lines which intersect to form a right angle. |
| Parallel Lines | Two coplanar lines which do not intersect. |
| Skew Lines | Two non-complanar lines which do not intersect. |
