Cut a cylindrical steel with a length of 1.2 meters and a base radius of 1 decimeter into 3 sections, how many square decimeters will the surface area increase?
把一根长1.2米，底面半径1分米的圆柱形钢材截成3段，表面积增加了多少平方分米？
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 4</gadget>
<output>12.56</output>

<result>12.56</result>