After cutting a circular piece of paper with a diameter of 6 cm, assemble it into an approximate rectangle whose width is equal to the radius. What is the perimeter of this rectangle?
把一个直径是6厘米的圆形纸片剪开后，拼成一个宽等于半径的近似长方形．这个长方形的周长是多少？
<gadget id="calculator">3.14 * 6</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 + 6</gadget>
<output>24.84</output>

<result>24.84</result>