Cut a largest square from a circle with a circumference of 12.56 meters, what is the area of the square in square decimeters?
在一个周长为12.56米的圆里剪一个最大的正方形，正方形的面积是多少平方分米．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">2 * 1 * 4 * 100</gadget>
<output>800</output>

<result>800</result>