IT-CESENATICO 1990 Problem 4

Let $a,b,c$ be side lengths of a triangle with $a+b+c = 1$ . Prove that $a^2 +b^2 +c^2 +4abc \le \frac12$ .

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.