设正方形边长为X,则FGH=nX,
过C作CH⊥BC地H,交GF于K,
易得ΔABC是直角三角形,
∴CH=12/5,CK=12/5-X,
∵GF∥BC,
∴ΔCGF∽ΔCAB,
∴CK/CH=GF/BC,
(2.4-X)/2.4=nX/5,
2.4nX=12-5X
(2.4n+5)X=12,
X=12/(2.4n+5)=60/(12n+25),
答:
设正方形边长为X,则FGH=nX,
过C作CH⊥BC地H,交GF于K,
易得ΔABC是直角三角形,
∴CH=12/5,CK=12/5-X,
∵GF∥BC,
∴ΔCGF∽ΔCAB,
∴CK/CH=GF/BC,
(2.4-X)/2.4=nX/5,
2.4nX=12-5X
(2.4n+5)X=12,
X=12/(2.4n+5)=60/(12n+25),
答: