Given: Angle L N O ≅ Angle L N M Angle O L N ≅ Angle M L N

Prove: Angle L N O ≅ Angle L N M

Triangles L O N and L M N share common side L N. Angles O L N and N L M are congruent. Angles O N L and L N M are congruent.
It is given that angle LNO is congruent to angle
and angle OLN is congruent to angle
. We know that side LN is congruent to side LN because of the
. Therefore, because of
, we can state that triangle LNO is congruent to triangle LNM.