The diameter of the small circle is equal to the radius of the large circle. The sum of the circumferences of these two circles is 18.84 cm. What is the area of the large circle in square centimeters?
小圆的直径相当于大圆的半径，这两个圆的周长和是18.84厘米，大圆的面积是多少平方厘米．
<gadget id="calculator">2 * 1</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>