The length of a square measured on a drawing with a scale of 1:5000 is 5 cm and the width is 4 cm. What is the actual area of the square?
在比例尺是1：5000图纸上量的一个广场的长是5厘米，宽是4厘米，这个广场的实际面积是多少．
<gadget id="calculator">1 / 5_000</gadget>
<output>1/5_000 = around 0.0002</output>

<gadget id="calculator">5 / (1/5_000) / 100</gadget>
<output>250</output>

<gadget id="calculator">4 / (1/5_000) / 100</gadget>
<output>200</output>

<gadget id="calculator">250 * 200</gadget>
<output>50_000</output>

<result>50_000</result>