How do we use the special segments in triangles?

We use three special segments which are, altitude, angle bisector and median.

Altitude: A line that goes through a vertex and is perpendicular to the base
Angle bisector: Divides angle into two congruent adjacent angles
Median: Connects the vertex of an angle to the midpoint of the opposite side

Altitude

Angle bisector

Median

http://intermath.coe.uga.edu/dictnary/descript.asp?termID=13

http://www.mathwords.com/a/angle_bisector.htm

http://library.thinkquest.org/C006354/4_3.html