There is a largest square in a circle with a diameter of 6 cm, calculate the area of the square.
在直径是6厘米的圆中有一个最大正方形，计算正方形的面积．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">6 * (3/2) * 2</gadget>
<output>18</output>

<result>18</result>