Question

If two parallel lines are cut by a transversal, then alternate interior angles are _?_.

Short answer

If two parallel lines are cut by a transversal, then alternate interior angles arecongruent.

Step-by-step solution

Step 1. Consider the following diagram.

Step 2. Find the theorem or postulate that can be used.

If the two parallel lines are cut by a transversal, then the alternate interior angles are congruent.

Step 3. Use the theorem.

$m\left|\right|n$and the transversal l cuts the two parallel lines m and n.

The interior alternative angles are∠1 and∠2.

Hence, $\angle 1\cong \angle 2$, that is, they are congruent.