Answer:
ΔABD ≅ ΔACD by SAS, therefore;
[tex]\overline {BD} \cong \overline {CA}[/tex] by CPCTC
Step-by-step explanation:
The two column proof is presented as follows;
Statement [tex]{}[/tex] Reason
ABCD is a trapezoid [tex]{}[/tex] Given
[tex]\overline {BA} \cong \overline {CD}[/tex] [tex]{}[/tex] Given
[tex]\overline {BC} \parallel \overline {AD}[/tex] [tex]{}[/tex] Definition of a trapezoid
ABCD is an isosceles trapezoid [tex]{}[/tex] Left and right leg are equal
∠BAD ≅ ∠CDA [tex]{}[/tex] Base angle of an isosceles trapezoid are congruent
[tex]\overline {AD} \cong \overline {AD}[/tex] [tex]{}[/tex] Reflexive property
ΔABD ≅ ΔACD [tex]{}[/tex] By SAS rule of congruency
[tex]\overline {BD} \cong \overline {CA}[/tex] [tex]{}[/tex] CPCTC
CPCTC; Congruent Parts of Congruent Triangles are Congruent
SAS; Side Angle Side rule of congruency
