The hour hand of a big clock in a customs building is 1.8 meters long. From 11 am to 4 pm, how many meters does the tip of the hour hand move?
某海关大楼的大钟时针长1.8米，从上午11点到下午4点，时针的尖端移动了多少米？
<gadget id="calculator">150 / 360</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">2 * 3.14 * 1.8 * (5/12)</gadget>
<output>4.71</output>

<result>4.71</result>