a) P=a*h*1/2
a= 3,5 cm h= 1,5 cm
P=3,5*1,5*1/2= 35/10*15/10*1/2= 7/2*3/2*1/2=21/4*1/2= 21/8= 2 i 5/8 [cm2]
b) P=(a+b)*h*1/2
a=4,5 cm b=1,5 cm h=2,5 cm
P= (4,5+1,5)*2,5*1/2 = 6*2,5*1/2 = 15*1/2 = 7,5 [cm2]
