Given: ABD = CDB which of the following must be true if the triangle are congruent?
PLZZZZ

C. AB ║ DC
The congruence of the two triangles means ∠ABD≅∠CDB. These, then, are alternate interior angles on either side of transversal BD between lines AB and DC. If alternate interior angles are congruent, the lines are parallel:
... AB ║ DC
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Congruence of the triangles does not require ∠B to be bisected or that it be 90°.
All the three sides of the given triangles are equal to the sides of another triangle then, [tex]\rm \overline{AB}=\overline{DC}[/tex]. Therefore the correct option is C).
Given :
Triangle ABD is congruent to the triangle CBD.
A triangle has three sides and the sum of all the interior angles are equal to [tex]180^\circ[/tex].
If the triangle ABD is congruent to the triangle CBD then:
AB = DC
AD = BC
BD = BD
If all the three sides of the given triangles are equal to the sides of another triangle then, [tex]\rm \overline{AB}=\overline{DC}[/tex]. Therefore the correct option is C).
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