In a rectangle with a length of 6 cm and a width of 3 cm, cut the largest semicircle, then what is the circumference of the semicircle in cm?
在长6cm，宽3cm的长方形内，剪一个最大的半圆，那么半圆的周长是多少cm．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<gadget id="calculator">9.42 + 6</gadget>
<output>15.42</output>

<result>15.42</result>