Geometry

Question Analysis

This question involves determining the relationship between given angles under the condition that AB ∥ CD. The focus is on understanding the properties of parallel lines cut by a transversal.

Key Concept Explanation:

When two parallel lines are cut by a transversal:

Alternate interior angles are on opposite sides of the transversal and inside the two lines. The key property is that alternate interior angles are congruent.

Same-side interior angles on the same side of the transversal and inside the two lines. The key property is that same-side interior angles are supplementary.

Option Analysis:

The correct figure is Option D:

∠3 and ∠4 are alternate exterior angles. Since AB ∥ CD, they must be congruent. (Alternate Exterior Angles Theorem)

So this option is correct.

The other options are incorrect: