A,B,C,D
BC = AB +CD //2
CD =3AB
AD=18cm
a)AC= AB +BC
BC=AB+CD //2
CD=3AB ==> BC= AB+3AB //2
BC=4 AB//2
BC= 2AB
AC= AB+BC
AC= 3AB } ===> C mij [AD] deoarece AC=DC
DC= 3AB } ===>C mij [AD] deoarece AC=DC
b) AB=? BC=? CD= ?
AC= 3AB
DC= 3AB
AD= AC+CD
AD= 6AB
18 cm = 6AB
AB= 3cm
BC= 2AB
BC= 6cm
CD= 3AB
CD = 9cm