A cylinder has a radius of 2 decimeters and a height of 10 decimeters. If the cylinder is cut into two sections along the horizontal direction, how much will the surface area increase?
一个圆柱半径是2分米，高是10分米，把圆柱沿水平方向切成两段，表面积增加了多少．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>