Respuesta :

1. AC ~= BC, angle(ACD) ~= angle(BCD)
Given

2. CD ~= CD
Reflexive property

3. triangle(ACD) ~= traingle(BCD)
SAS

4. AD ~= BD
CPCFC (congruent parts of congruent figures are congruent)

5. angle(DAE) ~= angle(DBE)
Properties of isosceles triangle