A cylindrical material with a base diameter of 20 cm is sawn into 2 sections, how much does the surface area increase in square centimeters
一根圆柱形材料，底面直径20厘米，把它锯成2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 * 2</gadget>
<output>628</output>

<result>628</result>