Dilation of a Triangle: Dynamic GeoGebra Demonstration

① This example dynamically demonstrates the dilation (scaling) of a triangle about a center point O with a scale factor k, showing the original triangle and its image side by side. ② The core mathematical concept is dilation, a similarity transformation that preserves shape while changing size, with corresponding vertices lying on lines through the dilation center. ③ Construction highlights: the Polygon command creates the original triangle poly1; the Dilate command generates the image triangle poly1' centered at O with factor k; auxiliary lines (OrthogonalLine, Intersect) and angles (Angle) label corresponding elements; LaTeX texts (text1–text4) display the scale factor and vertex coordinates; a slider k controls the scaling interactively. ④ Suitable for middle and high school students and teachers exploring similarity transformations, geometric construction, or dynamic geometry software, ideal for classroom demonstrations or self-guided investigation of dilation properties.