A square and a rectangle have the same perimeter. The side length of the square is 9 cm. The length of the rectangle is 11 cm. What is the width in cm?
一个正方形和一个长方形的周长相等，正方形的边长是9cm，长方形的长是11cm，宽是多少cm．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<gadget id="calculator">18 - 11</gadget>
<output>7</output>

<result>7</result>