## Cyclic Quadrilateral Rectangle Result

The respective intersections *E*, *F*, *G* and *H* of the angle bisectors of angles *A*, *B*, *C* and *D* of a cyclic quadrilateral *ABCD*, with the circumcirle, form a rectangle.

(Drag any of the red points).

Is the result also true if *ABCD* becomes a crossed quadrilateral?

1) Can you explain (prove) why *EFGH* is a rectangle?

2) Can you apply or generalize the result to a cyclic hexagon? Go to *Cyclic Hexagon Application & Generalization*.

If stuck, read my paper *An interesting cyclic quadrilateral result*.

Created with Cinderella

Michael de Villiers, 16 May 2011.