Gradient of a Straight Line

This GeoGebra example provides an interactive visual demonstration of the gradient (slope) of a straight line and its geometric interpretation. The core mathematical concept is the slope of a linear function, defined as the ratio of vertical change to horizontal change between two points on the line, along with related coordinate geometry topics such as linear equations, midpoints, and perpendicular lines. The construction uses GeoGebra commands including Line to draw the line, Slope to display its gradient value, OrthogonalLine to create perpendiculars, Intersect to find intersection points, Polygon to form auxiliary triangles, Midpoint to locate midpoints, and Vector to represent direction. Dynamic points A, B, and P allow users to drag and adjust the line, observing how the slope changes in real time. This resource is suitable for middle and high school students learning linear functions and coordinate geometry, and serves as an effective classroom demonstration tool for teachers to illustrate the relationship between slope and line inclination.