Wittenbauer's parallelogram

Knowledge about Plane Geometry and PolygonsSuppose that the sides of a (black) quadrilateral are trisected. Form a new (magenta) quadrilateral whose sides are defined by the four pairs of points of trisection on either side of the vertices of the original quadrilateral; it is always a parallelogram. Drag the vertices of the black quadrilateralComponente Curricular::Ensino Fundamental::Séries Finais::Matemátic