The radius of the bottom of a cylinder is 2 decimeters, and the height is 10 decimeters. If the cylinder is cut into two sections parallel to the horizontal direction of the upper and lower bottom surfaces, how much is the surface area increased?
一个圆柱底面半径是2分米，高是10分米，把圆柱平行于上、下底面水平方向切成两段，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>