Prove-

Statements-
3. AB ||CD
4. ANGLE ABD = CDB
5. DB = DB
6. ABD = CDB
Reason-
3.?
4.?
5.?
6.?

Proof:

3. Given: AB || CD (Given parallel lines)

4. Given: ∠ABD = ∠CDB (Given corresponding angles are equal)

5. Reflexive Property of Equality: DB = DB (Any quantity is equal to itself)

6. Angle Equality Property: ∠ABD = ∠CDB (If two angles are equal to the same angle, then they are equal to each other)

Therefore, we have proved that ABD = CDB.