When drawing a circle, the distance between the two legs of the compass is 2 cm. What is the circumference of the semicircle drawn in cm?
画圆时圆规两脚叉开的距离是2厘米，画出半圆的周长是多少厘米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">2 * 3.14 * 1</gadget>
<output>6.28</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>