The diameter of a circle is 2 cm. Divide it into several equal parts and put them together to form an approximate rectangle. What is the perimeter of this rectangle in cm?
一个圆的直径是2厘米，把它平均分成若干份后拼成一个近似的长方形，这个长方形的周长是多少厘米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 + 1</gadget>
<output>4.14</output>

<gadget id="calculator">4.14 * 2</gadget>
<output>8.28</output>

<result>8.28</result>