The diameter of a circular flower bed measured on a drawing with a scale of 1:2000 is 4 cm. What is the actual area of this circular flower bed in square meters?
在比例尺是1：2000的图纸上量得一个圆形花坛的直径是4厘米，这个圆形花坛的实际面积是多少平方米．
<gadget id="calculator">1 / 2_000</gadget>
<output>1/2_000 = around 0.0005</output>

<gadget id="calculator">4 / (1/2_000) / 100 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 ** 2</gadget>
<output>1_600</output>

<gadget id="calculator">3.14 * 1_600</gadget>
<output>5_024</output>

<result>5_024</result>