如图所示,设BF为a,FC=b,D到GH的高为h1,G到BC的高为h2
则有ah1=3,bh2=5
S三角形PBD=S三角形ABD-S平行AEPH-S三角EPD-S三角PHB
=(a+b)*(h1+h2)/2-3-ah2/2-bh1/2
=(ah1+bh2)/2-3
=(3+5)/2-3
=4-3
=1
如图所示,设BF为a,FC=b,D到GH的高为h1,G到BC的高为h2
则有ah1=3,bh2=5
S三角形PBD=S三角形ABD-S平行AEPH-S三角EPD-S三角PHB
=(a+b)*(h1+h2)/2-3-ah2/2-bh1/2
=(ah1+bh2)/2-3
=(3+5)/2-3
=4-3
=1