Question

1. why is the angle opposite the intersection x?

adjacent angles can be congruent
vertical angles are congruent
a linear pair of angles are supplementary
opposites attract

Explanation:

Vertical angles are formed when two lines intersect. They are opposite each other and have equal measures. In the context of triangle angle sum proofs (which often use line intersections and angle relationships), the property that vertical angles are congruent is relevant for establishing angle - measure equalities. Adjacent angles (sharing a common side) are not necessarily congruent. A linear pair (adjacent angles forming a straight line) are supplementary (sum to \(180^{\circ}\)), not necessarily congruent. "Opposites attract" is a non - geometric, non - mathematical concept in this context.

Answer:

Vertical Angles are Congruent