AC=BD=4sqrt(2)
EK=AC
TP|| AC
TP=(1/2) AC=[b]2sqrt(2)[/b]
MD=5
DF=(3/4)BD=3sqrt(2)
MF^2=MD^2+DF^2=5^2}+(3sqrt(2))^2=25+18=43
MF=sqrt(43)
Из подобия Δ WAE и Δ WDM:
2:6=AE:5
AE=(5/3) ⇒ OQ=(5/3)
QF^2=OQ^2+OF^2=(5/3)^2+(sqrt(2)^2=(25/9)+2=43/9
⇒ QF=[b]sqrt(43)/3[/b]
MQ=sqrt(43)-(sqrt(43))/3=[blue]2sqrt(43)/3[/blue]
S_( Δ ЕМК) =(1/2)EK*MQ=(1/2)*4sqrt(2)*[blue]2sqrt (43)/3[/blue]=2sqrt(86)/3
S_(трапеции ТЕКР)=(1/2) (EK+TP)*QF=(1/2)(4sqrt(2)+2sqrt(2))*[b]sqrt(43)/2[/b]=3sqrt(86)/2
S_(cечения)=S_( Δ ЕМК) + S_(трапеции ТЕКР)=(2sqrt(86)/3)+(3sqrt(86)/2)=13sqrt(86)/6