Triangles can be classified by their angles and/or side lengths. Use the chart below to help you name triangles.
| Classify by the lengths of their sides | Classify by the measures of their angles |
| Equilateral has 3 congruent sides | A Right triangle has 1 right angle |
| Isosceles has 2 congruent sides | An Acute triangle has 3 acute angles |
| Scalene has no congruent sides | An Obtuse triangle has 1 obtuse angle |
Hint:
right angle = exactly 90º
acute angle = more than 0º but less than 90º
obtuse angle = more than 90º but less than 180º
straight angle = exactly 180º
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