How many iron sheets are needed to make two uncovered buckets with a base radius of 3 decimeters and a height of 8.5 decimeters?
做两个底面半径为3分米，高8.5分米的无盖水桶，需用多少铁皮？
<gadget id="calculator">2 * 3.14 * 3 * 8.5</gadget>
<output>160.14</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<gadget id="calculator">160.14 + 28.26</gadget>
<output>188.4</output>

<gadget id="calculator">188.4 * 2</gadget>
<output>376.8</output>

<result>376.8</result>