va rog fin tot sufletul dau coroana
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a)P(ABCD)=20cm.
ABCD-trapez isoscel⇒AD≡BC.
P(ABCD)=AB+BC+CD+AD=6+4+2·AD=20
10+2AD=20 |-10
2AD=10⇒AD=10/2=5cm.
b)P(ABCD)=24cm
ABCD-trapez isoscel⇒AD≡BC.
P(ABCD)=AB+BC+CD+AD=6+4+2AD=24
2AD=14⇒AD=14/2=7cm.
c)P(ABCD)=30cm
ABCD-trapez isoscel⇒AD≡BC.
P(ABCD)=AB+BC+CD+AD=6+4+2AD=30
2AD=20⇒AD=20/2=10cm.