Notam cu a b c
a- lungimea
b- latimea
c- h( inaltimea)
a=20 cm = 2 dm
b=30 cm = 3 dm
c= 40 cm = 4 dm
Ab=2*3 = 6 dm²
Al 1 = 2*4 = 8dm²
Al 2 = 3*4 = 12dm²
At= (Ab+Al1+Al2)
Al=2(6+8+12) = 52 dm²
1flac.......13dm2
x flac.......52 dm2
x=52/13 = 4 flacoane
Sper ca te am ajutat!!!