If Utah is angle a and Colorado is angle b and Arizona is angle c and New Mexico is angle d Angle a and d are vertical angles angle b and c are vertical angles
Vertical angles are pairs of angles formed when two lines intersect and are situated opposite each other. At the Four Corners, the pairs of vertical angles are Angle A (Utah) with Angle D (New Mexico) and Angle B (Colorado) with Angle C (Arizona). These angles are congruent, meaning they have the same measure.
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