A rectangular iron frame has a circumference of 16 meters and a width of 2 meters. Find its length?
一个长方形铁架，周长16米，宽2米，求它的长？
<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<result>6</result>