Question

Pe 4 va rog frumos !!
Dau coroana !!

Answer 1

$AE=FB=BG=HC=CI=JD=DK=LA=x=3 cm\\AB=BC=CD=DA=LG=KH=EJ=FI=y=12 cm\\EL=KJ=IH=GF=t\\EF=GH=IJ=KL=z\\y=x+z+x=2x+z=>z=y-2x=12-3*2=12-6=6 cm\\A_{LEJK}=A_{FGHI}=\frac{(z+y)x}{2}=\frac{(6+12)3}{2}=\frac{18*3}{2}=27 cm^2\\A_{EFIJ}=z*y=12*6=72 cm^2\\A=A_{LEJK}+A_{FGHI}+ A_{EFIJ}=27+27+72=126 cm^2\\t^2=x^2+x^2=2x^2=2*3^2=2*9=>t=\sqrt{2*9}=3\sqrt2cm\\P=t+t+t+t=4t=4*3\sqrt2=12\sqrt2cm$