Types of Triangles Lesson
The 6 Main Types of Triangles: by Side and by Angle
Triangles types are named and classified by their sides and by their angles.
- Acute Triangle — All angles are less than 90°.
- Right Triangle — Has an angle that is exactly 90°.
- Obtuse Triangle — Has one angle that is more than 90°.
- Equilateral Triangle — All three sides are equal in length.
- Isosceles Triangle — Two sides are equal in length.
- Scalene Triangle — Has no sides that are equal in length.