A conical pile of stones has a base diameter of 8m and a height of 3m. What is the area of the stone pile?
一近似于圆锥形的石子堆的底面直径是8m，高3m．石子堆的占地面积是多少？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>