Vertical Angles, are angles that are opposite to each other that shares the same vertex. The vertex in the image is where the two lines cross.
[tex]\begin{gathered} \angle2\text{ and }\angle4\text{ are vertical angles} \\ \angle1\text{ and }\angle3\text{ are vertical angles} \end{gathered}[/tex]
Vertical Angles have a property where they are congruent. So whatever is the measurement of one angle, it would be the same to its vertical angle pair.
[tex]\begin{gathered} m\angle1=m\angle3 \\ m\angle1=86.7\degree \\ \text{and} \\ m\angle2=m\angle4 \\ m\angle2=93.3\degree \end{gathered}[/tex]
