SOLUTION:
a. The triangles at A have 2 sides marked to be congruent, and 2 angles marked to be congruent, However, if we look closely, there is a second set of congruent angles. These angle are congruent by
b. The triangles both have a 90 degree angle nested between 2 sides;
Thus the triangles are congruent by;
c. The two triangles have all sides equal, so the triangles are congruent by;