a*b
7,5cm*3cm =22,5cm2
5,5dm*5,5dm = 30,25dm2
a*h
9m*4m= 36dm2
3,2cm*3cm= 9,6cm2
a+b*h :2
((13m+11m)*5m):2 = 60m2
(e+f) :2
(8dm+4dm) :2= 6dm2
a*h :2
5cm*11cm :2= 27,5cm2
12cm*5cm :2= 30cm2
