The diameter of a semicircular flower bed is 12m, what is its circumference in m?
一个半圆形花坛的直径是12m，它的周长是多少m．
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">3.14 * 6</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 + 12</gadget>
<output>30.84</output>

<result>30.84</result>