<Tri-2024-2122>, hint

Line p,q,r cut QR, RP, PQ in D', E',F' respectively.

Triangles DEF and PQR are similar, <RPQ=<FDE=180-2A, 

Line e through E, parallel to PD' cuts BC in D" .Then PQ//DE, PD'// ED".

<DED"=90-<EDD"=90-A. Hence PD' is internal angle bisector of <QPR.

PD' QE' RF' meet at one point, incenter of triangle PQR.