Triangles with Equal Area Between Parallel Lines

This interactive example demonstrates the geometric principle that triangles sharing the same base and situated between two parallel lines always have equal areas, regardless of the position of the third vertex. The core mathematical concept focuses on the area formula of a triangle and the constant distance between parallel lines. The construction employs GeoGebra commands such as Line for parallel boundaries, Polygon for triangle creation, and Area/Perimeter for real-time calculations, with LaTeX for professional mathematical notation. It is an ideal teaching tool for middle school geometry to visualize the relationship between height, base, and area.