连结AC
S△ABC=24/2=12
S△ABE=5
S△AEC=7
BE:EC=5:7
EC=7/12*BC
S△ACD=12
S△AFD=6
S△ACF=6
DF:FC=1:1
FC=1/2*CD
设CD为X,BC为Y
XY=24
S△CEF=[X/2*(7/12*Y)]=7XY/48=7*24/48=3.5
S△AEF=24-5-6-3.5=9.5平方厘米
连结AC
S△ABC=24/2=12
S△ABE=5
S△AEC=7
BE:EC=5:7
EC=7/12*BC
S△ACD=12
S△AFD=6
S△ACF=6
DF:FC=1:1
FC=1/2*CD
设CD为X,BC为Y
XY=24
S△CEF=[X/2*(7/12*Y)]=7XY/48=7*24/48=3.5
S△AEF=24-5-6-3.5=9.5平方厘米