Geometry · Points, Lines & Angles
Angle
HSG-CO.A.1
Definition
A figure formed by two rays sharing a common endpoint, called the vertex.
Examples
- Angle ABC is formed by rays BA and BC meeting at vertex B.
- The middle letter in a named angle, like ABC, is always the vertex.
Key rule
The middle letter of an angle's name always names the vertex.
Memory hook
Two rays, one shared corner.