The perimeter of a rectangle is 240 cm, and the ratio of length to width is 2:1, what is the length of the rectangle in cm?
一个长方形的周长是240厘米，长与宽的比是2：1，这个长方形的长是多少厘米．
<gadget id="calculator">240 / 2</gadget>
<output>120</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">120 * (2/3)</gadget>
<output>80</output>

<result>80</result>