Angle Practice Studio.
Estimate angles, test geometric relationships, and reveal answers. Toggle a virtual protractor to practice manual reading.
Single Angle Practice
Estimate the angle type and magnitude, then click to reveal answers.
Understanding Angles & Relationships.
Master the geometric properties of angles, unit conversions, and real-world applications.
Acute Angle
An angle that measures strictly between 0° and 90°. Examples include 30° roof pitches, scissor openings, and 60° equilateral triangles.
Right Angle
An angle of exactly 90° (π/2 radians), forming a quarter circle. Found in square corners, picture frames, and perpendicular street grids.
Obtuse Angle
An angle that measures greater than 90° but less than 180°. Found in reclined chairs, wide roof gables, and clock hands at 4:00.
Straight Angle
An angle of exactly 180° (π radians), forming a flat straight line. Represents half of a complete rotation.
Reflex Angle
An angle strictly greater than 180° and less than 360°. Represents the major outer arc measured by a 360° full-circle protractor.
Complete Angle (360°)
A full 360° rotation where the ray completes a complete circle back to the 0° baseline. Forms a full turn (1.0 Turn = 400 gon = 2π rad).
Angle Pairs
• Complementary: Sum equals 90° (a + b = 90°).
• Supplementary: Sum equals 180° (a + b = 180°).
360° Explementary Angles
Two angles whose sum is 360° (a + b = 360°). Divided into 4 quadrants: Q I (0–90°), Q II (90–180°), Q III (180–270°), and Q IV (270–360°).