Track / Stage 4 / 301 of 340 #561 of 2000

30. (FRG 5) Prove that a convex polyhedron all of whose faces are equilateral triangles has at most 30 edges.

This one wants a proof. Work it on paper, read the official solution, then mark yourself honestly — the ladder only means something if the record is true.

I solved it I didn't Skip

Official solution

None

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.