If the circumference of a semicircle is 10.28 cm, what is the radius of the circle in cm?
一个半圆的周长为10.28cm，那么圆的半径为多少cm．
<gadget id="calculator">3.14 + 2</gadget>
<output>5.14</output>

<gadget id="calculator">10.28 / 5.14</gadget>
<output>2</output>

<result>2</result>