The radius of the large circle is equivalent to the diameter of the small circle, and it is known that the area of the large circle is 9.42dm**2 larger than that of the small circle. What is the area of the great circle in square decimeters?
大圆的半径相当于小圆的直径，已知大圆面积比小圆面积多9.42dm**2．大圆的面积是多少平方分米？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">9.42 / 3</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>