An angle is formed when two rays meet at a shared endpoint called the vertex. Think of it like two arms stretching out from the same shoulder.
We measure angles in degrees (°). A full spin all the way around is 360°. A quarter turn is 90°. A half turn is 180°.
Angles show up everywhere — the corner of a book, the hands of a clock, the slope of a roof. Once you start noticing them, they're impossible to miss.
Remember
The size of an angle depends only on how much the two rays are spread apart — not how long the rays are.
Real World
When you open a laptop lid, the angle between the screen and the keyboard changes as you open it wider. At a quarter of the way open, that's roughly 45°. Fully flat is 180°.
Feeling ready?
Put this concept to work with a practice workout.