If the diameter of a circle is 2 centimeters, what is its area in square centimetres? (π is calculated with 3.14)
一个圆的直径是2厘米，则它的面积是多少平方厘米．(π用3.14计算)
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>