Cut a cylinder with a height of 8cm into two equal half cylinders along the diameter of the bottom surface, the area of the cross section is 40cm**2, how many square centimeters is the side of the cylinder?
把一个高为8cm的圆柱沿底面直径切割成两个相等的半圆柱，截面的面积是40cm**2，这个圆柱的侧面是多少平方厘米？
<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<gadget id="calculator">3.14 * 5 * 8</gadget>
<output>125.6</output>

<result>125.6</result>