The diameter of a semicircle is 12 cm, what is the circumference of the semicircle?
一个半圆的直径是12厘米，这个半圆的周长是多少米．
<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>

<gadget id="calculator">30.84 / 100</gadget>
<output>0.3084</output>

<result>0.3084</result>