In which diagram are angles 1 and 2 vertical angles?

Answer

First diagram shows  1 and 2 vertical angles

Explanation

From the all four diagrams,we get the diagram first shows the vertically opposite angles.  

angle 1 and angle 2 are vertically opposite angles

vertically opposite angles are equal in measurements. when two lines are intersect each other form four angles, out of this four angles two pairs of vertically opposite  angles are there.

All other figures  angle 1 and 2 shows adjacent angles.

i think 1: 2

step-by-step explanation: