RTΔABC∽RTΔACD ∠ACD+∠CAB=90°
(AD/AC)²+[BC/√(AC²+BC²)]²=1
AD²/AC²+BC²/(AC²+BC²)=1
108(AC²+48)+48AC²=(AC²+48)AC² ( AC²)²-108AC²-48×108=0
AC²=36 AC=6
RTΔABC∽RTΔACD ∠ACD+∠CAB=90°
(AD/AC)²+[BC/√(AC²+BC²)]²=1
AD²/AC²+BC²/(AC²+BC²)=1
108(AC²+48)+48AC²=(AC²+48)AC² ( AC²)²-108AC²-48×108=0
AC²=36 AC=6