On a map with a scale of 1:500,000, the distance on the map to measure the total length of the Hangzhou Bend Sea-crossing Bridge is 7.2 cm. How many kilometers is the actual length of this sea-crossing bridge?
在一幅比例尺是1：500000的地图上，量得杭州弯跨海大桥全长的图上距离是7.2厘米，这座跨海大桥的实际全长有多少千米．
<gadget id="calculator">1 / 500_000</gadget>
<output>1/500_000 = around 0.000002</output>

<gadget id="calculator">7.2 / (1/500_000) / 100_000</gadget>
<output>36</output>

<result>36</result>