Advanced Geometric Problem & Solution (Twice a week update) Now 4767 problems posted.
<Tri-2026-2314>, hint
<Tri-2026-2314>, general, collinear
<Singapore MO 2019>
<Tri-2026-2313>, hint
<Tri-2026-2313>, general, angle
<Singapore MO 2018>
<Tri-2026-2312>, hint