Angle Meaning & Classification

How the lesson starts: Angle Meaning & Classification

Dizzy's dance contest
Meet Dizzy, a dancing robot! Coach Luna calls out moves like "Spin a quarter turn!" and "Open your arms 30°!" But Dizzy doesn't know what degrees are yet. Let's teach Dizzy all about angles!
Acute, right, obtuse
An angle is two rays that meet at a vertex. Angles get names by size. Less than 90° is acute. Exactly 90° is a right angle, a square corner. Between 90° and 180° is obtuse. Exactly 180° is a straight angle.
Turns around the circle
One full spin, all the way around, is 360°. A quarter turn is 360 ÷ 4 = 90°. A half turn is 180°. A three-quarter turn is 3 × 90 = 270°. And a full turn brings Dizzy back to the start at 360°!