Without solving for "x", which criteria can be used to prove the triangles congruent? justify.

a) without solving for "x", the triangles cannot be proven congruent.
c) asa; right angles cad and ceb are congruent; ac≅ ec; vertical angles acd and ecb are congruent;
d) aas; right angles cad and ceb are congruent; ac≅ ec; vertical angles acd and ecb are congruent;

Two triangles are congruent if their corresponding sides have the same length and their corresponding angles have the same measurement.
 One of the cases that proves the congruence of triangles is the case:
 Angle-Side-Angle
 Two triangles are congruent if they have equal two of their respective angles and the side between them.
 Answer
 C) ASA; right angles CAD and CEB are congruent; AC≅ EC; vertical angles ACD and ECB are congruent;