a parallel line & mid-points
Line EF is a parallel line to line BC.Point A and D are on line EF.Point M and N are the mid-points.
Move point D to find the geometric quality of the lengthes (AD, BC, MN) .
Ā@You can also move points (A, B, C, D, E, F) on CABRI
Ā@Download CABRIáU data (d24) from here.