If a circular steel with a base diameter of 2 decimeters is cut into two sections, the surface area increases by how many square decimeters.
把一根底面直径是2分米的圆形钢材截成两段，表面积增加了多少平方分米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2</gadget>
<output>6.28</output>

<result>6.28</result>