If a cylinder with a base diameter of 4dm is cut into three small cylinders, how many square decimeters will the surface area increase?
将一个底面直径为4dm的圆柱截成三段小圆柱，表面积增加了多少平方分米？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 4</gadget>
<output>50.24</output>

<result>50.24</result>