$?解: 因為FG//AC , HI//AB?$
$?所以∠FPD=∠IEP,∠FDP=∠IPE?$
$?所以△FDP∽△IPE?$
$?因為△FDP、△IPE的面積分別為4、 9?$
$?所以\frac {S_{△FDP}}{S_{△IPE}}=(\frac {DP}{PE})2=\frac {4}{9}?$
$?所以\frac {DP}{PE}=\frac {2}{3}?$
$?同理可得,\frac {FP}{PG}=\frac {2}{7}?$
$?設(shè)DP=2x ,則PE=3x .?$
$?因為DP//BC , HI//AB?$
$?所以∠FPD=∠PGH ,∠DFP=∠HPG , ?$
$?所以△FDP∽△PHG?$
$?所以\frac {DP}{HG}=\frac {FP}{PG}=\frac {2}{7}?$
$?因為DP=2x, ?$
$?所以HG=7x?$
$?因為FG//AC , HI//AB , DE//BC?$
$?所以四邊形DPHB和四邊形PECG都為平行四邊形?$
$?所以BH=DP=2x,CG=PE=3x,?$
$?所以BC=BH+HG+CG=12x?$
$?因為DE//BC,F(xiàn)G//AC,?$
$?所以∠FDP=∠B ,∠DFP=∠A?$
$?所以△FDP∽△ABC?$
$?所以\frac {S_{△FDP}}{S_{△ABC}}=(\frac {DP}{BC})2=(\frac {2x}{12x})2=\frac {1}{36}?$
$?因為S_{△FDP}=4 ,?$
$?所以S_{△ABC}= 144?$