Question

problem 14: (first taught in lesson 24)
from this given statement, select the definition, property, postulate, or theorem that justifies the prove statement.
given: $overline{bc}paralleloverline{ad}$
prove: $angle dab$ and $angle b$ are supplementary.

Explanation:

Given $\overline{BC}\parallel\overline{AD}$, $\angle DAB$ and $\angle B$ are same - side interior angles formed by the transversal $\overline{AB}$ intersecting the parallel lines $\overline{BC}$ and $\overline{AD}$. By the property that if two parallel lines are cut by a transversal, then same - side interior angles are supplementary, we can prove that $\angle DAB$ and $\angle B$ are supplementary.

Answer:

If two parallel lines are cut by a transversal, then same - side interior angles are supplementary.