Selçuk Biçer, Geometria Super Top, https://www.facebook.com/photo/?fbid=29791214137134644&set=gm.2401516107285411&idorvanity=830782544358783

 

Nelson Tunala, Geometria Super Top, https://www.facebook.com/photo?fbid=28604658082509297&set=gm.1762162808377358&idorvanity=293155508611436

 

Training Geometry Olympiad, Own(?) https://www.facebook.com/photo?fbid=28680326304954903&set=gm.1758790032047969&idorvanity=293155508611436

 

https://artofproblemsolving.com/community/c4t48f4h2582826_cka_bkab_cb2_905436__2021_3rd_kvanta_mo_85_ukraine

 

https://gogeometry.com/school-college/6/p1583-proving-parallel-lines-secants-circles-cyclic-quadrilateral-geometry-education.html

 

Geometria Super Top, Dong le Minh https://www.facebook.com/photo?fbid=4516632665291447&set=gm.2394306588006363&idorvanity=830782544358783

 Note: I came up with the following proof 53 years ago, during an exam; as the majority of solvers used the 3 concurrent circumcircles of the  equilateral triangles and their centers, I doubt my proof was correctly appreciated, because I only got 15 pts out of 20, while the math work was perfect, and the physics one of at least 7 of 10! 

Aops, https://artofproblemsolving.com/community/c6t48f6h3909405_mathematics