Question

ateral abcd is a parallelogram
9
what are the missing statement and reason in step 2 of the proof?
a. statement: $overline{ab}paralleloverline{cd},overline{bc}paralleloverline{ad}$ reason: definition of a parallelogram
b. statement: $angle baccongangle acd$ reason: alternate interior angles theorem
c. statement: $overline{ab}congoverline{cd},overline{bc}congoverline{ad}$ reason: given
d. statement: $\triangle abccong\triangle cda$ reason: sss criterion for congruence

Explanation:

A parallelogram is defined as a quadrilateral with two - pairs of parallel sides. Given that ABCD is a parallelogram, the first property that follows from the definition is that $\overline{AB}\parallel\overline{CD}$ and $\overline{BC}\parallel\overline{AD}$.

Answer:

A. Statement: $\overline{AB}\parallel\overline{CD},\overline{BC}\parallel\overline{AD}$; Reason: definition of a parallelogram