AM²+BM²+CM²=2AM+2BM+2CM-3等价于：（AM-1)²+（BM-1）²+（CM-1）²=0AM>0,BM>0,CM>0所以,满足上式的AM=1,BM=1,CM=1根据余弦定理,设CM与AB的夹角为θ,则∠CMA=π-θ所以：AC²=AM&#...