It is known that the sum of the radii of the two circles is 6 cm, and the circumference of the larger circle is 25.12 cm. What is the area of the smaller circle?
已知两圆半径之和是6厘米，大圆周长25.12厘米，小圆的面积是多少．
<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

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

<result>12.56</result>