1.
an angle relationship where the two angles are “across” an intersection from each other and have the same degree measure
2.
an angle relationship where the two angles add up to 180 degrees
3.
an angle relationship where the two angles add up to 90 degrees
4.
an angle relationship where the two angles share a vertex and a ray
5.
the “corner” of an angle
6.
the plural form of “vertex”
9.
the unit of measure for angles