If a piece of round steel with a bottom radius of 8cm is sawed into two pieces, its surface area will be increased by how many cm**2.
把一段底面半径是8cm的圆钢锯成两段，它的表面积就增加了多少cm**2．
<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">3.14 * 64 * 2</gadget>
<output>401.92</output>

<result>401.92</result>