如果已知圆柱的底面半径 r ，以及高 h ，则可计算出圆柱的侧面积 s=2πrh ，体积 v=π r 2 h 。其中 π=3.1415926 -Known cylinder of the radius r, and high-h, you can calculate the cylinder side of the area s = 2πrh, volume v = of π r 2 h. Where π = 3.1415926