A semicircle has an arc length of 6.28 cm, what is the circumference of the semicircle in cm?
一个半圆，弧长6.28厘米，这个半圆形的周长是多少厘米．
<gadget id="calculator">6.28 / 3.14</gadget>
<output>2</output>

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

<gadget id="calculator">6.28 + 4</gadget>
<output>10.28</output>

<result>10.28</result>