Answer: Choice B. Angle 3
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Explanation:
Angles 1 and 3 are vertical angles. Note how line t and line r intersect to form an X shape. Angle 1 and angle 3 are opposite angles in this X configuration, which is what makes them vertical angles. Vertical angles are always congruent.
Angle 1 is congruent to angle 2 if and only if both angles were 90 degrees (note the angles are supplementary). Otherwise, they aren't congruent. That allows us to rule out choice A. Choice C is ruled out for the exact same reason.
