מעגלים חוסמים משולשים הנוצרים מאלכסוני מרובע

Use the scroll bar to unfold the problem. The diagonals of the quadrilateral divide it into four triangles. What happens when you connect the centers of the circumscribing circles of the mentioned triangles? Does this property hold for concave quadrilaterals as well? Try proving it! (there are hints in the following worksheet in this book)