There is a rectangular open space in the school. It is known that the length is 12 meters and the width is half of the length. The staff of the surveying company walked 2 times along the edge of the rectangular open space. How many meters did they walk in total?
学校有一块长方形的空地，已知长12米，宽是长的一半，测量公司的工作人员沿着这块长方形空地的边缘走了2圈，一共走了多少米？
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">12 + 6</gadget>
<output>18</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

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

<result>72</result>