Răspuns:
Explicație pas cu pas:
DF= 10cm→AF=18-10=8 cm
DE=20cm→EC=35-20=15cm
DE║AM→conform teoremei asemanarii →Δ ADF≈ ΔAFM
DF/AF= EF/ MF= DE /AM
CN║DF→conform teoremei asemanarii ΔDEF≈ΔCEN
DE/EC= FE/EN =DF/CN
10/8=EF/MF =20/AM
MF=8EF/10=4EF/5
AM= (20*8):10
AM=160:10
AM=16cm
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b)
20/15=EF/EN = 10/CN
EN= 15EF/20
CN= (15*10)/20
CN= 150:20
CN= 7,5 cm
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c)
P ΔBMN= BC+CN+MN+AM+AB
110= 18+7,5+MN+16+35
110-76,5=MN
MN= 33,5 cm
