We are given the following triangle:
We are given that:
Since RS is a bisector this means that:
Also, since S is a midpoint of PQ:
By the reflexive property we have:
Since we have two pairs of congruent angles this means that:
Therefore, by SAS theorem of congruency:
Since the triangles are congruent this means that all of its sides are congruent too, therefore:
And thus we have concluded the proof.