Answer:
ΔABD ≅ ΔACD by SAS, therefore;
by CPCTC
Step-by-step explanation:
The two column proof is presented as follows;
Statement Reason
ABCD is a trapezoid Given
Given
Definition of a trapezoid
ABCD is an isosceles trapezoid Left and right leg are equal
∠BAD ≅ ∠CDA Base angle of an isosceles trapezoid are congruent
Reflexive property
ΔABD ≅ ΔACD By SAS rule of congruency
CPCTC
CPCTC; Congruent Parts of Congruent Triangles are Congruent
SAS; Side Angle Side rule of congruency