The circumference of a semicircle is 10.28 meters, what is the area of the semicircle?
一个半圆周长10.28米，半圆的面积是多少．
<gadget id="calculator">10.28 / 5.14</gadget>
<output>2</output>

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

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

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

<result>6.28</result>