Expand menu menu_open Minimize Go to startpage home Home History history History expand_more
{{ item.displayTitle }}
navigate_next
No history yet!
Progress & Statistics equalizer Progress expand_more
Student
navigate_next
Teacher
navigate_next
{{ filterOption.label }}
{{ item.displayTitle }}
{{ item.subject.displayTitle }}
arrow_forward
{{ searchError }}
search
{{ courseTrack.displayTitle }} {{ printedBook.courseTrack.name }} {{ printedBook.name }}

Concept

# Angle

When two rays share an endpoint, an angle is formed. Below, the rays $\overrightarrow{BA}$ and $\overrightarrow{BC}$ create angle $ABC.$

When referring to a specific angle, the notation $\angle$ is often used to name the angle. Additionally, $m\angle$ is used to note the size or measure of an angle, which can be interpreted as the amount of turn in the rotation between the rays. It is often measured in degrees, but can also be measured in radians. An angle of $0 ^\circ$ shows no rotation, while an angle of $360 ^\circ$ shows a complete rotation.

Sometimes, the space outside an angle — rather than inside — is of interest. In figure above, $\alpha$ measures the interior angle formed by the rays, whereas $\beta$ measures the exterior angle.