Use two iron wires of the same length, both of which are 10.28 decimeters long, to form a semicircle and a square respectively. What is the difference in area between them?
用两根同样长的铁丝，长度都是10.28分米，分别围成一个半圆和一个正方形，它们的面积相差多少平方分米．
<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">10.28 / 4</gadget>
<output>2.57</output>

<gadget id="calculator">2.57 * 2.57</gadget>
<output>6.6049</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>

<gadget id="calculator">6.6049 - 6.28</gadget>
<output>0.3249</output>

<result>0.3249</result>