A rectangle and a square each have the same perimeter. The side length of the square is 6 cm and the width of the rectangle is 4 cm. What is the length of this rectangle in centimeters?
长方形和正方形各一个，它们的周长相等．已知正方形的边长是6厘米，长方形的宽是4厘米．这个长方形的长是多少厘米？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<result>8</result>