Question 4
Let $ABC$ be a triangle with $\angle B>90^\circ$, and let $E,F$ be the feet of the altitudes from $B,C$, respectively. Can line $EF$ be tangent to the $A$-excircle?
Proposed by Ankan Bhattacharya, Zack Chroman, Anant Mudgal. Evan Chen’s third-party compilation; source discussion https://aops.com/community/p12195848.
Proposed by Ankan Bhattacharya, Zack Chroman, Anant Mudgal. Evan Chen’s third-party compilation; source discussion https://aops.com/community/p12195848.