Parallel & Perpendicular Lines in the Coordinate Plane by David DeShetler

①This interactive GeoGebra example dynamically demonstrates the properties of parallel and perpendicular lines in the coordinate plane, allowing students to explore slope relationships through hands-on manipulation. ②Core mathematical concepts include the slope of a line, the equality of slopes for parallel lines, the negative reciprocal relationship for perpendicular lines, and using slopes to determine line positions. ③Construction details: The example uses GeoGebra commands Point, Line, and Slope to create lines and their slope objects, along with text objects (text1, text2) and a button (button1) to provide key questions and interactive prompts. Objects include f, A, B, C, b, a, m, m_1. ④Suitable for middle school to high school students learning coordinate geometry or linear equations, and ideal for quick classroom discovery activities where teachers can guide students to drag points, observe slope changes, and verify conditions for parallelism and perpendicularity.