The angle 3 is vertical with angle 1 .
Vertical angles are a pair of non-adjacent angles formed by the intersection of two lines and a transversal.
In the context of intersecting parallel lines, consider two angles, angle 1 and angle 3, that share a common vertex where the transversal intersects the parallel lines.
These angles are separated by the transversal and are distinct from one another.
Such angles are referred to as vertical angles.
In the given scenario, angle 1 and angle 3 are vertical angles because they meet the criteria for verticality.
They share the same vertex at the point of intersection and are positioned on opposite sides of the transversal.
The nature of vertical angles is such that they are always congruent, meaning they have equal measures.
Therefore, if angle 1 measures a certain number of degrees, angle 3 will also measure the same number of degrees.
The concept of vertical angles is crucial in geometry, particularly when dealing with parallel lines and transversals.
Recognizing and utilizing the properties of vertical angles contribute to solving geometric problems and proving theorems related to angles formed by intersecting lines.