Use 3 squares of the same size to form a rectangle. The perimeter of the rectangle is 16 cm. What is the length of the rectangle in cm?
用3个大小一样正方形拼成一个长方形，拼成后长方形周长是16厘米，这个长方形的长是多少厘米．
<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>