A median of a triangle is a line segment from a vertex of the triangle to the mid point of the side opposite that vertex.
1. the three medians always meet at a single point, i.e. centroid of the triangle
2. each median divides the triangle into two smaller triangles of equal area.
3. the centroid is the center of the gravity of the triangle.
4. the three medians divides the triangle into 6 smaller triangles that all have the same area , even though they may have different shapes.
Altitude: altitude of a triangle is the perpendicular distance from any of its vertices to the opposite sides.
perpendicular bisector of a triangle: is a line segment that passes through the mid point of the side of a triangle and also the perpendicular to the side.
bisector of a triangle: angle bisector of a triangle is the line which bisects its interior angle.
hope this helps you.