Radian–Degree Conversion on a Circle

This GeoGebra example demonstrates the equivalence between degree measure and radian measure by visualizing both systems on the same circle. It helps learners build an intuitive geometric understanding of why “degrees convert to radians” the way they do. The core mathematics includes the radian definition via arc length relative to radius, circle central angles, and the conversion between degree (°) and radian (rad) units. Construction highlights drawn from the command summary: Circle is used to create one or more circles (e.g., r1, r2 with common center O and related circle objects), while Sequence and Point generate tick/reference points and angle rays (including objects like ticks, P, Q, R, and a). Segment supports drawing connecting elements such as radii or reference lines. CircleArc is used to render the relevant arc to anchor the angle measurement visually. The example also uses label/scale objects such as ticksRadian, ticksRadianLabels, deg, and d, along with optional text elements (text1–text5, Off1) to present synchronized markings in both units. Suitable for middle school through early college trigonometry lessons and for classroom demonstrations or independent study of unit conversion and the geometric meaning of radian measure.