A cylindrical glass vessel with a bottom radius of 6 cm contains a portion of water, and a conical plumb weight 9 cm high is immersed in the water. When the lead weight is removed from the water, the water level drops by 0.5 cm. What is the area of the base of this conical plumb bob?
一个底面半径是6厘米的圆柱形玻璃器皿里装有一部分水，水中浸没着一个高9厘米的圆锥形铅锤．当铅锤从水中取出后，水面下降了0.5厘米．这个圆锥形铅锤的底面积是多少平方厘米？
<gadget id="calculator">3.14 * 36 * 0.5</gadget>
<output>56.52</output>

<gadget id="calculator">3 / 9</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">56.52 * (1/3)</gadget>
<output>18.84</output>

<result>18.84</result>