Given that the radius of a circle is 12 cm, what is the area of the circle?
已知圆的半径为12cm，这个圆的面积是多少？
<gadget id="calculator">12 ** 2</gadget>
<output>144</output>

<gadget id="calculator">3.14 * 144</gadget>
<output>452.16</output>

<result>452.16</result>