The area ratio of the big and small circles is 9:1, and the difference in circumference is 12.56 cm. What is the difference in the areas of the two big and small circles?
大、小两个圆的面积比是9：1，周长相差12.56厘米，则大小两圆的面积相差多少．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">12.56 / 2 / 3.14 / 2</gadget>
<output>1</output>

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

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">3.14 * 1 * 8</gadget>
<output>25.12</output>

<result>25.12</result>