Cut out 4 identical and as large as possible circles from a square paper with a side length of 12 cm. What is the area of each circle in square centimeters?
用一张边长12厘米的正方形纸剪出4个完全相同并尽可能大的圆，每个圆的面积是多少平方厘米．
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>