Error problem.

parmenides51 wrote: Given two acute triangles $\vartriangle ABC, \vartriangle DEF$. If $AB \perp DE, BC \perp EF$ and $CA \perp FD$, show that the area of $\vartriangle ABC$ is not less than the area of $\vartriangle DEF$ The original question is totally different. It says Given two acute triangles $\triangle ABC, \triangle DEF$. If $AB\ge DE, BC\ge EF$ and $CA\ge FD$, show that the area of $\triangle ABC$ is not less than the area of $\triangle DEF$. which is obvious by Heron's formula.

oops, my fault, I shall correct this, thanks for noticing you two above