cuboid steel ingot, the circumference of the bottom surface is 20 decimeters, the ratio of length to width is 4:1, and the height is 45% less than the width. It can just be cast into a cone with a height of 6 decimeters. What is the area of the bottom of the cone? decimeter squared?
一块长方体钢锭，底面周长是20分米，长与宽的比是4：1，高比宽少45%，它正好可以铸成高为6分米的圆锥体，圆锥体的底面积是多少平方分米？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">10 * (4/5)</gadget>
<output>8</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">2 * (11/20)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">8 * 2 * (11/10)</gadget>
<output>88/5 = around 17.6</output>

<gadget id="calculator">3 / 6</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(88/5) * (1/2)</gadget>
<output>44/5 = around 8.8</output>

<result>44/5 = around 8.8</result>