A problem by Jafar Nikpour, Geometria adictiva, https://www.facebook.com/photo/?fbid=1563991670925449&set=pcb.496539223435526

 

An aops problem

 A solution without headache calculations, just angle chase:

aops

 

Training Geometry Olympiad, from Gogeometry

 

Gogeometry, 1582

 

aops, https://artofproblemsolving.com/community/c4t48f4h3451217_angle_chase_equal_sides_far_apart

 

Romantics of Geometry, Thanasis Gakopoulos,

 

Math for Change, Doaa Jayab, Trazo Geometrico Maldito

 

aops, nice problem, super proof

 

Math for Change, Trazo Geometrico Maldito

 A nice and easy solution

aops

 

Geometria Super Top, Jose B. Sepulveda,

 

Geometria Super Top, Hakan Ersoz

 

Floor van Lamoen, Pery Geometrico

 

Ercole Suppa, posted by Mohammad Bayezid Beg

 

https://gogeometry.blogspot.com/2023/09/geometry-problem-1554-finding-length-of.html

 

Gogeometry, pb 1569

Peru Geometrico, Math for Change

 

Prob 1576 Gogeometry

 

Fernando Teixeira, Geometria Super Top

 

https://www.facebook.com/photo/?fbid=8176415442484570&set=a.1012350578891128

 

Gogeometry, 1577

 

Math for Change, Trazo Geometrico Maldito

 

Romantics of Geometry, Thanasis Gakopoulos

 Pls see that notations are slightly different!

https://artofproblemsolving.com/community/c6t48f6h3405388_a_proof_from_geometry

 

2 aops problems

 

Nelson Tunala, Geometria (solo trazos)

 

Jafar Nikpour, Training Geometry Olympiad

 

Levent Divriklinoglu, Sorunun-zoru

 Below a synthetic solution, little bit obscure, lacking calculations/explanations

Sorunun-zoru, Levent Devriklinoglu

 

Peru Geometrico, Stanley Rabinowitz, Square and 2 equilateral triangles

 

an aops problem

 

SR, Peru Geometrico, Aug. 10th 2024

 

Sorunun Zoru

 

Thanasis Galopoulos, Romantics of Geometry, https://www.facebook.com/photo/?fbid=2178549955855245&set=gm.7888812937899010&idorvanity=1019808738132832

 

One of my old problems

 For <BAC=20 I shall post my synthetic solution later on

Problem: https://artofproblemsolving.com/community/c4t48f4h3352797_an_alright_geo_problem

 

Naibe Oliveira, Training Geometry Olympiad

 

https://www.facebook.com/groups/970715314297475/permalink/1206897867345884

 With my son paramount observation

Geometria (solo trazos), Razan Al Haddad, https://www.facebook.com/photo?fbid=431799229393013&set=gm.1807980529693318&idorvanity=179005525924168

 

https://www.facebook.com/photo/?fbid=6785852008183973&set=pcb.6785868758182298, prob. 6

Classical mathematics, https://www.facebook.com/photo/?fbid=8411977608816959&set=gm.1402771007057882&idorvanity=340992303235763

 A fast solution

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

Binh Luc, Peru Geometrico, https://www.facebook.com/photo/?fbid=10228034844329488&set=gm.7197648463681318&idorvanity=400828670030032

 See the drawing and explanation attached.

Best regards.