Adjacent Angles

Adjacent angles are two angles that have a common vertex and a common side but do not overlap.

In the figure, $\angle 1\text{ and }\angle 2$ are adjacent angles.

They share the same vertex and the same common side.

In the figure, $\angle 1\text{ and }\angle 3$ are non-adjacent angles.

They share a common vertex, but not a common side.

Angles $\angle 1\text{ and }\angle 2$ are non-adjacent angles.

They share common side, but not a common vertex.