Open Middle Slope Exercise: Constructing Line Slope with Conditions

This example demonstrates an open-ended “middle-point” slope exploration in the coordinate plane, where constraints and conditional choices lead students to visualize how line slope emerges as a difference ratio. It centers on core ideas such as slope (rise over run), the geometric meaning of a linear equation, and how varying/choosing conditions affects the constructed configuration. The construction uses GeoGebra commands and interactive objects: PointIn, Line, Segment, and Polygon to define key points and connecting segments; Slope to compute and display the slope; Textfield to present calculated values or guidance text; and Mode together with If to switch construction/display behavior based on user inputs. Inputs are controlled via InputBox1/InputBox2 and actions such as button1/button2, while the overall set of objects (points and derived items like d, c, b, a, e, A, n, m, and auxiliary labels) organizes the geometry for clear graphing. Suitable for middle school through early college-level lessons on coordinate geometry, linear functions, and interactive graphing practice.