What is the perimeter of a rectangle whose length is 24 cm and whose length is 12 cm greater than its width?
长是24厘米，长比宽多12厘米的长方形的周长是多少？
<gadget id="calculator">24 - 12</gadget>
<output>12</output>

<gadget id="calculator">24 + 12</gadget>
<output>36</output>

<gadget id="calculator">36 * 2</gadget>
<output>72</output>

<result>72</result>