Answer:
Besides the givens:
12.
AC = EC, BC = DC; Definition of Midpoint
<ACB = <ECD; Vertical Angles Theorem
Triangle ABC = Triangle EDC; SAS Congruence Postulate
13.
AD = CD; Definition of Median
BD = BD; Reflexive Property
Triangle ABD = Triangle CBD; SSS Postulate
Explanation:
None necessary.