Răspuns:
Explicație pas cu pas:
AH=AF=(1/2)·AB=24cm, BH=BG=(1/2)·AB=24cm, CG=CE=(1/2)·CD=6cm, DE=DF=(1/2)·CD=6cm.
a) Atunci AD=AF+DF=24+6=30cm
b) EH=h=2R=CM. In ΔBCM, BM=BH-MH=24-6=18cm. ⇒CM²=BC²-BM²=30²-18²=(30-18)(30+18)=12·48=12²·4 ⇒BM=12·2=24cm=h=2R, ⇒R=12cm.
c) Aria(ABCD)=(AB+CD)·h/2=(48+12)·24/2=30·24=720cm².
