Angles on Circle
Launch this tool in a distraction-free environment optimized for classroom instruction.
About
What is Angles on Circle?
Angles on Circle is a purely mathematical interactive simulation designed to visually prove core geometric circle theorems. By freely dragging points along the circumference of a circle, users can dynamically observe the relationships between central angles, inscribed angles, and tangents. The live, real-time measurements update instantly, allowing students to test hypotheses and immediately see mathematical laws in action.
Using it in class
This tool is specifically engineered for geometric proofs, replacing static textbook diagrams with manipulatable, high-visibility data.
Mathematics: The Inscribed Angle Theorem
Demonstrate that an angle inscribed in a circle is exactly half of the central angle that subtends the same arc. By dragging the central points (A and B) or the inscribed point (P), students can watch the measurements update and verify that the ratio always remains exactly 2:1, no matter where point P is dragged on the major arc.
Mathematics: Alternate Segment Theorem
By toggling the "Tangent Line" feature, teachers can visually construct the Alternate Segment Theorem. Students can observe the relationship between the angle formed by a chord and a tangent, and compare it to the inscribed angle in the alternate segment.