The ratio of the radii of the two circles is 2:3. The sum of the areas of the two circles is 260 square centimeters. What is the area of the smaller circle?
两个圆的半径比是2：3，两个圆的面积和是260平方厘米，较小圆的面积是多少．
<gadget id="calculator">4 + 9</gadget>
<output>13</output>

<gadget id="calculator">4 / 13</gadget>
<output>4/13 = around 0.307692</output>

<gadget id="calculator">260 * (4/13)</gadget>
<output>80</output>

<result>80</result>