Peru Geometrico, Thanos Kalogerakis, https://www.facebook.com/photo/?fbid=10228283504905847&set=gm.7435626976550131&idorvanity=400828670030032

 A very nice approach by my son, A.M. Fulger

https://artofproblemsolving.com/community/c4t48f4h3318242_rioplatense_angle_chasing_geometry_for_juniors_2023_l1_p2

 A surprising solution given by my son, attached

https://artofproblemsolving.com/community/c6h616123p3670325

 This is my synthetic proof to the subject problem:

https://artofproblemsolving.com/community/c6t48f6h3304019

 

https://artofproblemsolving.com/community/c4t48f4h3294054_geometry7

 Attached, my solution... Ooops! So far it's wrong!

https://www.facebook.com/photo?fbid=418692704036999&set=gm.1648363175934045&idorvanity=830782544358783

 

2 problems, https://artofproblemsolving.com/community/c4t48f4h3300850_geometry

 See attached, synthetic solutions for the 2 problems posted there