Question

vertical angles are always ____. total 180 degrees; adjacent angles; acute; congruent (equal measures)

Explanation:

To determine the correct answer, we analyze each option:

• "total 180 degrees": Vertical angles don't always sum to 180° (supplementary angles do).
• "adjacent angles": Vertical angles are opposite, not adjacent.
• "acute": Vertical angles can be any measure (acute, obtuse, right), not always acute.
• "congruent (equal measures)": By the vertical angles theorem, vertical angles are always congruent.

Answer:

D. congruent (equal measures)