The sum of the circumferences of the big and small circles is 18.84cm, and the circumference of the small circle is half of the circumference of the large circle, what is the radius of the small circle?
大小两圆的周长之和是18.84cm，小圆的周长是大圆周长的一半，则小圆的半径为多少．
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<result>1</result>