Given that the area of a semicircle is 25.12cm**2, what is the circumference of the semicircle in centimeters?
已知半圆的面积是25.12cm**2，那么这半圆的周长是多少厘米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 4 * 1</gadget>
<output>12.56</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">12.56 + 8</gadget>
<output>20.56</output>

<result>20.56</result>