How many centimeters of iron wire are needed to bind three logs with a radius of 20 cm together?
将三根半径为20厘米的圆木捆在一起，至少需要多少厘米的铁丝．
<gadget id="calculator">2 * 3.14 * 20</gadget>
<output>125.6</output>

<gadget id="calculator">20 * 2 * 4</gadget>
<output>160</output>

<gadget id="calculator">125.6 + 160</gadget>
<output>285.6</output>

<result>285.6</result>