Angle Builder Lab
Set angles from 0° to 360°, watch the SVG update in real time, and classify each angle. Record your findings to discover the rules that separate acute, right, obtuse, straight, and reflex angles.
Guided Experiment: Angle Builder Lab
What do you think determines whether an angle is acute, right, obtuse, straight, or reflex? Write your prediction before you start exploring.
Write your hypothesis in the Lab Report panel, then click Next.
Angle Explorer
Benchmark angles
Controls
Data Table
(0 rows)| # | Degrees | Angle Type | Turn Name | Supplementary Pair (°) |
|---|
Reference Guide
Angle Types
Acute: Greater than 0° and less than 90°. Sharp corner.
Right: Exactly 90°. The corner of a square or book.
Obtuse: Greater than 90° and less than 180°. Wider than a right angle.
Straight: Exactly 180°. A flat, straight line.
Reflex: Greater than 180° and less than 360°. More than a half turn.
Full turn: Exactly 360°. One complete rotation back to the start.
Landmark Angles and Turns
90°. Quarter turn. One corner of a square.
180°. Half turn. A straight line pointing the other way.
270°. Three-quarter turn. Like turning left three times.
360°. Full turn. Back to where you started.
Supplementary Angles
Two angles are supplementary when they add up to 180°. For any angle A less than 180°, its supplementary partner is 180° - A.
Example: 60° and 120° are supplementary because 60 + 120 = 180.
Reflex angles (greater than 180°) do not have a supplementary partner between 0° and 180°.
Investigation Tips
Start at 0° and drag slowly to 360°. Notice exactly where the type changes.
Try the benchmark buttons (30°, 45°, 60°...) to hit common angles quickly.
Record at least two angles from each type before writing your conclusion.
The boundaries between types are at exactly 90°, 180°, and 360°. These are the only angles that belong to a single special category.