MathNet 2023-part-06 — 191 problems (EN–VI) Question 170

Let $n = 2m + 1$ for some integer $m$. $n$ points $A_1, A_2, \dots, A_n$ are chosen on two parallel lines. What is the largest possible number of acute triangles among the triangles $A_iA_jA_k$ over $1 \le i \lt j \lt k \le n$?