Here is the completed two-column proof with the statements and reasons placed correctly:
| Statement | Reason | |------------------------------------------------------------------|-----------------------------------------------------| | 1. ABCD is a parallelogram. | Given | | 2. DB¯¯¯¯¯¯¯¯≅AC¯¯¯¯¯¯¯¯ | Given | | 3. DA¯¯¯¯¯¯¯¯≅CB¯¯¯¯¯¯¯¯ | Opposite sides of a parallelogram are congruent. | | 4. AB¯¯¯¯¯¯¯¯≅BA¯¯¯¯¯¯¯¯ | Reflexive Property of Congruence | | 5. △BAD≅△ABC | SSS Congruence Theorem | | 6. ∠BAD≅∠ABC | Corresponding parts of congruent triangles are congruent. | | 7. m∠BAD=m∠ABC | Definition of congruence | | 8. m∠BAD+m∠ABC=180° | Consecutive angles of a parallelogram are supplementary | | 9. m∠BAD+m∠BAD=180° | Substitute m∠ABC for m∠BAD from step 7 | | 10. 2m∠BAD=180° | Combine like terms | | 11. m∠BAD=90° | Division Property of Equality | | 12. m∠ABC=90° | Transitive Property of Equality | | 13. m∠ADC=m∠DAB=90° | Opposite angles of a parallelogram are congruent | | 14. ∠BAD , ∠DCB , ∠ABC , and ∠ADC are right angles | Definition of a right angle | | 15. ABCD is a rectangle | Definition of a rectangle |
This sequence lists the statements and their corresponding reasons in the proper order for the proof that parallelogram ABCD with congruent diagonals is indeed a rectangle.