Similar Triangles (Part 1): Dynamic Proportionality and Corresponding Angles

① This example demonstrates the properties of similar triangles through two dynamically scaled triangles, showing that corresponding angles are equal and corresponding sides are proportional. ② Core mathematical concepts include similarity criteria, proportional relationships, linear equations, and straight-line equations in the coordinate plane. ③ Construction highlights: using GeoGebra commands Segment, Polygon, and Angle to build two triangles, with a slider ScaleFactor controlling the scaling of the second triangle, while displaying corresponding angles α, β, γ, δ, ε, ζ and side ratios via text objects. ④ Suitable for middle school or early high school students learning similarity, and for teachers demonstrating the effect of scale factors and proportional reasoning, laying groundwork for trigonometry and coordinate geometry.