Are alternate interior angles congruent?

1 Answer
BRIAN M.
May 6, 2017

Yes alternate interior angle are congruent if the lines cut by the transversal are parallel.

Explanation:

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In the diagram above #/_ c# and #/_f# are alternate interior

#/_c + /_d = 180^o# linear pair angles are supplementary

#/_f + /_d = 180^o# consecutive interior angles are supplementary

therefore #/_c = /_f#

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