2×5^2×3.14+2×5×3.14×12^啥意思？底面积=πr^2=5*5*3.14=78.5cm^2圆柱面积=2πrh=2*3.14*5*12=376.8cm^2总面积=2*底面积+圆柱面积=2*78.5+376.8=533.8cm^2