There is a circular fish pond with a diameter of 12 meters, what is its area in square meters?
有一个圆形鱼池的直径是12米，它的面积是多少平方米．
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">3.14 * 36</gadget>
<output>113.04</output>

<result>113.04</result>