This comprehensive geometry tutorial breaks down the specific definitions and properties of four critical line segments associated with triangles: the median, altitude, perpendicular bisector, and angle bisector. Using clear, hand-drawn diagrams, the narrator explains the unique characteristics of each segment, such as how a median connects to a midpoint while an altitude forms a right angle. The video carefully distinguishes between often-confused terms by highlighting visual markers like tick marks for congruence and squares for right angles.