Interactive Practice on Circle Equations: Random Target Circle with Input Verifi

① This interactive GeoGebra example demonstrates how to determine a circle from its center and radius, and verifies whether the user's input matches the randomly generated target circle. ② The core mathematical concept is the standard equation of a circle (x-h)²+(y-k)²=r², involving center coordinates, radius, coordinate geometry, and random generation. ③ Construction highlights: uses GeoGebra commands such as Circle to draw the circle, Random to generate random centers and radii, Textfield and button for user input, OrthogonalLine and Intersect for auxiliary verification, and Element/Dimension to handle random arrays. Objects include targetCircleCoef, YourCenter, YourRadius, and various text/button elements for feedback. ④ Suitable for middle school (advanced) or high school students, this example reinforces circle equation concepts and serves as an engaging classroom activity or self-study tool with immediate feedback.