The circumference of a semicircle is 20.56 decimeters. What is the radius of this semicircle in decimeters.
一个半圆的周长是20.56分米．这个半圆形的半径是多少分米．
<gadget id="calculator">20.56 / 5.14</gadget>
<output>4</output>

<result>4</result>