Unit Circle, Radians, and Degrees by Evan Schilling (3)

① This interactive GeoGebra example visually demonstrates the relationship between radians and degrees on the unit circle, showing how angles correspond to arc lengths and trigonometric values. ② Core mathematical concepts include the unit circle, radian measure, degree measure, trigonometric functions (sine, cosine, tangent), and the geometric interpretation of central angles. ③ Construction details: Using GeoGebra commands such as Intersect, Circle, Segment, Angle, and CircleArc, the construction includes a unit circle k, center B, a movable point A on the circle, angle α, arc c, and numerous auxiliary objects (points C, D, E, segments f, g, h, angle β, text labels text1 and text2, and many helper points F through U). By dragging point A or using a slider, the angle changes dynamically, and the corresponding radian and degree values are displayed in real time. ④ Suitable for high school or introductory college mathematics, this resource helps students grasp the definition of radians, convert between degrees and radians, and visualize trigonometric functions on the unit circle. It is ideal for classroom demonstrations or self-paced exploration.