1. Orthocentre: Point of intersection of the three altitude of the triangle is called the orthocentre of the triangle.
2. Centroid: Point of intersection of the three median of the triangle is called the centroid of the triangle.
3. Incentre: All the angle bisector of the triangle passes through same point is called the incentre of the triangle.
4. Circumcenter: The perpendicular bisector of the sides of the triangles passes through same point is called the circumcenter ofthe triangle.
5. Equilateral Triangle: A triangle whose all sides are equal and all angles are equal to 60 degree.
6. Isosceles Triangle: A triangle whose two sides are equal.
7. Scalene Triangle:A triangle having no equal angles and no equal sides.
8. Median: A line Segment joining the corner of the triangle to the midpoint of the opposite side of the triangle.
9. Altitude: A line Segment from the corner of the triangle and perpendicular to the opposite side of the triangle.
10. Right Triangle: Right triangle has one angle equal to 90 degree.
11. Obtuse Triangle: One angle is obtuse angle while other two are acute angles.
12. Acute Triangle: All the angles are acute.