There is a kind of oil pipeline, each section is 30 meters long and 0.5 meters in diameter, how many square meters of iron sheets are needed to produce 600 sections of such oil pipelines?
有一种油管，每节长30米，直径0.5米，生产这样的输油管600节，至少需要多少平方米的铁皮？
<gadget id="calculator">3.14 * 0.5 * 30 * 600</gadget>
<output>28_260</output>

<result>28_260</result>