The proof shows that ABCD is a rectangle. Which of the following is the missing reason? B A Prove: ABCD is a rectangle. Salements 1 ABD is a paralelogram with congruent diagonals 20 and BD. Reasons 1. Given: definition of congruence 3. Symmetric property Side-side side postulate 5 DE ZARA BAD End CDA are supplementary. 7. BAD and LCDA are nght angles. 8. ABOD is rectangle. 6. Consecutive angles of a parallelooram are supplementary, 7. Angles that are congruent and supplementary are right angles. 8. A parallelogram with one noht angle is a rectangle. QED A. Opposite angles of a parallelogram are congruent. B. Consecutive angles of a parallelogram are congruent. C. Consecutive sides of a parallelogram are congruent. D. Opposite sides of a parallelogram are congruent