In Exercises 19 and 20 , the triangles to be proved congruent have been redrawn separately. Congruent parts are marked.
a) Name an additional pair of parts that are congnuent by using the reason Identity.
b) Considering the congruent parts, state the reason why the triangles must be congruent.
$$\triangle M N P \equiv \triangle M Q P$$
(GRAPH CANT COPY)