Reflections Page 1: Interactive Triangle with Text Inputs

①This example demonstrates how to use three text input boxes in GeoGebra to control the coordinates of a triangle's vertices, allowing students to visually explore how reflection (mirror) transformations affect the shape's position. ②Core mathematical concepts include reflection symmetry in plane geometry, coordinate representation of points, and the relationship between input parameters and geometric transformations. ③Construction details: The Polygon command creates triangle poly1, three Textfield objects (InputBox1, InputBox2, InputBox3) serve as interactive inputs, and the Intersect command computes point D, enabling dynamic updates of the figure when coordinates are changed. ④Suitable for middle or high school geometry lessons, this interactive tool helps learners understand coordinate rules for reflections and introduces basic ideas of parameterized construction and dynamic exploration in mathematics.