If a cylinder with a diameter of 40 cm and a length of 2 meters is sawn into two pieces of 1 meter in length, the surface area will increase by how many square centimeters.
把一根直径40厘米，长2米的圆柱体木料锯成1米长的两段，表面积增加多少平方厘米．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 2</gadget>
<output>2_512</output>

<result>2_512</result>