A cuboid iron block with a length of 6 cm, a width of 4 cm, and a height of 5 cm is melted and cast into a cone with a height of 20 cm. What is the area of the base of the cone in square centimeters?
把一块长6厘米，宽4厘米，高5厘米的长方体铁块熔铸成一个高20厘米的圆锥，这个圆锥的底面积是多少平方厘米．
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">6 * 4 * 5 * (3/20)</gadget>
<output>18</output>

<result>18</result>