3.14*5*8+2*3.14*［（5\2）*（5/2）］
=3.14*5*8+2*3.14*[2.5*2.5]
=15.7*8+6.28*［2.5*2.5］
=125.6+6.28*6.25
=125.6+39.25
=164.85（平方厘米）求采纳！一个圆柱半径4cm高6cm计算表面积2*3.14*4*6+2*3.14*［4*4］=6.28*4*6+2*3.14*16=25.12*6+6.28*16=150.72+100.48=251.2求采纳好吧