| A | B |
|---|
| obtuse triangle | one of the angles of a triangle is an obtuse angle |
| right triangle | one of the angles of a triangle is a right angle |
| acute triangle | all three of the angles of a triangle are acute angles |
| equiangular triangle | all three angles of an acute triangle are congruent |
| equilateral triangle | all three sides of a triangle are congruent |
| isosceles triangle | at least two sides of a triangle are congruent |
| scalene triangle | no two sides of a triangle are congruent |
| regular triangle | all sides and all angles are congruent |
