There are two circles, the sum of their areas is 1991 square centimeters, the circumference of the small circle is 90% of the circumference of the large circle, what is the area of the large circle in square centimeters?
有两个圆，它们的面积之和为1991平方厘米，小圆的周长是大圆周长的90%，问大圆面积是多少平方厘米．
<gadget id="calculator">100 / 181</gadget>
<output>100/181 = around 0.552486</output>

<gadget id="calculator">1_991 * (100/181)</gadget>
<output>1_100</output>

<result>1_100</result>