Interactive Proof of Thales' Theorem

This GeoGebra example demonstrates Thales' Theorem: the angle subtended by a diameter of a circle is always a right angle (90°). Users can drag point C along the circle to observe that ∠ACB remains a right angle dynamically. Key mathematical concepts include the circle angle theorem, right triangle properties, and circle geometry. Construction details: Circle command creates circle o, Line command draws diameter AB, Point command places movable point C, Polygon command forms triangle ABC, Intersect command finds intersection points, InteriorAngles and Angle commands measure and display angles. This interactive construction is ideal for middle school geometry teaching, theorem exploration, classroom demonstration, and student investigation.