Answer:
BD ≅ BD
Alternate interior angles
ASA axiom
Explanation:
Prove that: ΔDAB ≅ ΔBCD
Statement (Reason in bracket)
1. ∡A ≅ ∡C ( Given)
2. BD ≅ BD (They are lengths of the same segment)
3. AB ║ CD (Given)
4. ∡ABD ≅ ∡∡DB (When a transversal crosses parallel lines, Alternate interior angles are congruent)
5 Δ DAB ≅ ΔBCD( ASA axiom of congruence)

[tex] \bold{Note}[/tex}
Some axioms that are needed to be the congruent triangle. These axioms are:
- Side-Angle-Side (SAS) axiom: If two sides and the included angle of one triangle are congruent to the corresponding two sides and included angle of another triangle, then the two triangles are congruent.
- Angle-Side-Angle (ASA) axiom: If two angles and the included side of one triangle are congruent to the corresponding two angles and included side of another triangle, then the two triangles are congruent.
- Side-Side-Side (SSS) axiom: If three sides of one triangle are congruent to the corresponding three sides of another triangle, then the two triangles are congruent.
- Hypotenuse-Leg (HL) axiom: If the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and the corresponding leg of another right triangle, then the two triangles are congruent.