- A line joining the midpoint of a side with the opposite vertex is called a Median.
- The point of intersection of the three medians is the Centroid.
- A perpendicular drawn from a vertex to the opposite side is called the Altitude.
- The point of intersection of the three altitudes is the Orthocentre.
- A line that bisects and also makes a right angle with the same side of the triangle is called a Perpendicular bisector.
-The three perpendicular bisectors of a triangle meet at a point called the Circumcentre.
- A circle drawn from this point with the circumradius would pass through all the vertices of the triangle.
- A line that divides the angle at one of the vertices into two equal parts is called an Angular bisector.
- The three angle bisectors of a triangle meet at a point called the Incentre of a triangle.
- The incentre is equidistant from the three sides, and a circle drawn from this point with the inradius would touch all the sides of the triangle.
