If a cylindrical piece of wood with a diameter of 20 cm is sawed into 3 sections, the surface area is increased by how many square centimeters.
把一根直径20厘米的圆柱形木头锯成3段，表面积增加多少平方厘米．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100 * 4</gadget>
<output>1_256</output>

<result>1_256</result>