上半部分是半球,下半部分是圆锥.
半球体积 = 1/2×4/3πR³ = 2/3×π×3³ = 18π
圆锥高h=√(5²-3²)=4
圆锥体积 = 1/3πR²h = 1/3×π×3²×4 = 12π
总体积 = 18π+12π=30π