Math Dictionary / Angle
Angle
An angle is formed by two rays that share the same endpoint.
GeometryGrade 4Grade 5Grade 6Grade 7Grade 8GEDSATACT
What it means
The shared endpoint is the vertex, and the opening between the rays is the angle.
Also called: angle measure
Examples
| A right angle measures 90 degrees |
| A straight angle measures 180 degrees |
| An acute angle is less than 90 degrees |
Common mistake
Do not call the side length of a shape an angle. An angle measures a turn or opening.
Try one
Question: What is the measure of a right angle?
Show answer
90 degrees.