If the circumference of a semicircle is 20.56 cm, what is the circumference of the entire circle in cm?
一个半圆的周长是20.56厘米，整个圆的周长是多少厘米．
<gadget id="calculator">3.14 * 8</gadget>
<output>25.12</output>

<result>25.12</result>