Types of Angles
Complete visual reference for acute, right, obtuse, straight, reflex and full rotation angles. Click any card to visualize it on the live protractor.
Open Protractor Tool →Types of Angles & Visual Guide
Angles are classified by their degree measurement. Click any card below to automatically load and visualize that angle directly on the interactive protractor.
Acute Angle
An angle that measures less than 90 degrees. Sharper than a square corner, commonly found in triangles, rooftop gables, and open scissors.
- •Slice of pizza (45°)
- •Hands of a clock at 2:00 (60°)
- •Rooftop truss pitch (30°–45°)
Right Angle
An angle measuring exactly 90 degrees. Formed by two perpendicular rays, creating a perfect square corner in architecture and carpentry.
- •Corner of a book or sheet of paper
- •Wall meeting a level floor
- •Crossroads intersection
Obtuse Angle
An angle measuring greater than 90 degrees but less than 180 degrees. Wider than a right angle, typical in open laptop screens and reclining seats.
- •Partially opened laptop screen (115°)
- •Reclining deck chair (120°)
- •Hands of a clock at 5:00 (150°)
Straight Angle
An angle measuring exactly 180 degrees. The two arms point in directly opposite directions, forming a continuous straight line.
- •Flat horizon line
- •Hands of a clock at 6:00
- •Straight horizontal ruler
Reflex Angle
An angle that measures more than 180 degrees and less than 360 degrees. Represents the larger outer rotation around an angle vertex.
- •Clock hands at 8:00 (external angle 240°)
- •Wide-open compass divider
- •Corner of an L-shaped room exterior
Full Rotation
A complete circular rotation around a point returning to the baseline ray, equal to 360 degrees or 2π radians.
- •One full turn of a wheel or gear
- •Clock hands completing 12 hours
- •Full circle navigation bearing