[ª] , [©] , [^] , [¨]Bisectors of four corners of quadrangle / Exploring correspondence(GC World : Various Problems ,Quadrangle¨Quadrangle)
Let's move point A, B, C, and D, and change quadrangle ABCD into various quadrangles.
What do you find?

GC/Win


Forum of Geometric Constructor by Y.Iijima