Draw a largest square in a circle with a radius of 6 cm. What is the area of the square in square centimeters?
在半径是6厘米的圆中画一个最大的正方形，正方形面积是多少平方厘米．
<gadget id="calculator">2 * 6 * 6</gadget>
<output>72</output>

<result>72</result>