(1)作∠DAC=30°AD交CB的延长线于点D,作BE⊥AD于点E,设BC=a
则BE=a,DE=a/√3, BD=2a/√3
∴CD=a + 2a/√3 = (√3 a+2a)/√3,
∴ AC= (√3 a+2a)
∴AB=√﹙a²+﹙√3a+2a﹚²﹚
=√2 a √(2√3 +4)
=√2a√(√3 +1﹚²
=﹙√6+√2﹚a
∴AN=(√6 +√2)a/2
由三角形相似知识,得
AM/AB=AN/AC
AM / [(√6 +√2)a]=½(√6 +√2)a / (√3 +2)a
AM=2a
∴BC=½ AM
(2)∵AB=8
∴﹙√6+√2﹚a=8
∴a=2(√6-√2)
AC=(√3 +2)·2(√6-√2)=2(√6+√2)
∴S△ABC=½ ×8×2(√6+√2)=48+8√2