If angle 1 and angle 5 are vertical angles and angle 1 equals 55, then angle 5 will equal

Hey there, and good morning to you! :D

Vertical Angles are angles that are congruent and have the same measure, and they usually form a straight line through the vertex. (if you were to draw through them) They actually share the same vertex.

So if angle 1 and angle 5 are vertical angles, and angle 1 equals 55 degrees,

then angle 5 will equal 55 degrees. 

I hope this helps!
~kaikers