Triangles: Classification
A triangle is a polygon with three sides.
Triangles can be classified by side length or by angle measure .


Equilateral Triangle  All sides congruent  
Isosceles Triangle  At least two sides congruent  
Scalene Triangle  No sides congruent 


Acute Triangle  All interior angles measure less than $90\xb0$  
Right Triangle  Exactly one interior angle measures $90\xb0$  
Obtuse Triangle  Exactly one interior angle measures more than $90\xb0$ 