A rectangle and a circle with a radius of 20 cm have the same perimeter. Given that the length of the rectangle is 40 cm, what is the width of the rectangle in cm?
一个长方形和一个半径是20厘米的圆的周长相等，已知长方形的长是40厘米，长方形的宽是多少厘米？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 20 * 1</gadget>
<output>62.8</output>

<gadget id="calculator">62.8 - 40</gadget>
<output>22.8</output>

<result>22.8</result>