Nikos Chitas, Training Geometry Olympiad, https://www.facebook.com/photo?fbid=122271007340215406&set=gm.1556187882308186&idorvanity=293155508611436

 

Belajar Matematika, Training Geometry Olympiad, https://www.facebook.com/photo/?fbid=122388556094011484&set=a.122193707846011484

 

https://www.facebook.com/photo?fbid=2222727324864324&set=gm.2046799649423727&idorvanity=830782544358783

 

AOPS, https://artofproblemsolving.com/community/c4h3766648p37197498

 

Geometria Super Top, Erdem Balkan, https://www.facebook.com/photo?fbid=10163296170008190&set=gm.2175894333180924&idorvanity=830782544358783

 

Erdem Balkan, Geometria Super Top, https://www.facebook.com/photo?fbid=25647127038321527&set=gm.2177790939657930&idorvanity=830782544358783

 

https://www.facebook.com/photo?fbid=926427346585289&set=gm.1553305082428012&idorvanity=544207276671136

I gave the following solution during December 1989!