## Geometry: Common Core (15th Edition)

The labeled right angle tells us that the angle formed by Park and 116th and the angle formed by 116th and Main. We know this because the angle formed by Park and Main and the labeled right angle are a linear pair. We know that the angle formed by 116th and Main measures 35, because it is a vertical angle to the angle that is labeled 35. If $\angle 1$ is the angle formed by Park and 116th, $m\angle1+35=90$ The subtraction property of equality gives us $m\angle1=55$