If a round steel with a bottom diameter of 6cm and a height of 20cm is sawed into two pieces, how much will the surface area increase in cm**2.
把一个底面直径是6cm、高是20cm的圆钢锯成两段，表面积增加多少cm**2．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9 * 2</gadget>
<output>56.52</output>

<result>56.52</result>