Diagonals of a parallelogram

It is well known in elementary Euclidean geometry, that diagonals of a parallelogram bisect each other.
  • Observe the construction steps by moving forward in the construction protocol. Scroll down meanwhile in the Algebra View if required.
  • Note that definitions of points E and F differ, but they are actually the same.
  • Drag point C to various positions. Try to find some positions which cause E to not be equal to F.
  • Check whether points E and F are equal by using the Relation Tool (in the 10th toolbox). Click "More" to investigate the situation symbolically.