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

I gave the following solution during December 1989!

I Love Geometry, Thanos Kalogerakis, https://www.facebook.com/photo.php?fbid=2379750322471099&set=p.2379750322471099&type=3

 

https://www.facebook.com/photo?fbid=10163232591639404&set=gm.1639486493871587&idorvanity=860672498419661

 The solution I found is too elegant to be left unposted! Enjoy it!

Aops, https://artofproblemsolving.com/community/c4t48f4h2582832_lines_in_a_trapezoid

 

AOPS, https://artofproblemsolving.com/community/c4t48f4h3757954_cyclic_quadrilaterals_strike_again

 

Sorunun_zoru, Levent Divriklioglu, https://www.facebook.com/photo?fbid=10163207014704404&set=gm.1634553914364845&idorvanity=860672498419661

 

I Love Geometry, Tieri Cruz, https://www.facebook.com/photo/?fbid=1341594994317304&set=gm.1444413630741448&idorvanity=307436207772535