The difference between the areas of the two circles is 247cm**2. It is known that the ratio of the circumference of the small circle to the circumference of the large circle is 9:10. What is the area of the large circle in square centimeters?
两个圆的面积之差为247cm**2，已知小圆周长与大圆周长的比是9：10，那么大圆的面积是多少平方厘米？
<gadget id="calculator">100 - 81</gadget>
<output>19</output>

<gadget id="calculator">247 / 19</gadget>
<output>13</output>

<gadget id="calculator">13 * 100</gadget>
<output>1_300</output>

<result>1_300</result>