If the largest circle is drawn in a square with a side length of 6 cm, what is the area of the circle in square centimeters?
在一个边长6厘米的正方形内画一个最大的圆，则这个圆形的面积是多少平方厘米．
<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>