a)
R=OA=12:2=6 dm
r=O'A'=2 dm
h=OO'=3 dm
ducem A'B _I_ AO
AB=6-2=4 dm
G=√(3²+4²)=√25=5 dm
Al=πG(R+r)=π×5(6+2)=40π dm²
b)
V=πh(R²+r²+R×r)/3=π×3(6²+2²+6×2)/3=π(36+4+12)=52π dm³
Vapa=52π×75%=39π≈122,46 dm³ ≈ 122,46 litri < 125 litri
1 dm³ = 1 litru
c)
A'O'/AO=VO'/VO VO'=x
2/6=x/(x+3)
6x=2x+6
4x=6
x=1,5
VO=1,5+3=4,5 dm