# Definitions
| Term  | Description                                                                                                                                                                                                                              |
| ----- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Ray   | Directed line segment consisting of an endpoint and a direction. Notated as $\overrightarrow{EF}$, where $E$ denotes the endpoint and $F$ denotes a point along the ray.                                                                 |
| Angle | Union of two rays with a common endpoint. Notated as $\angle DEF$ or $\angle FED$, where $D$ and $F$ are along the points of each ray, and $E$ is the vertex. $\angle EFD$ is not valid notation, because the vertex must be the middle. |
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