A square swimming pool, its side length is 9 meters, Xiao Ming ran around the swimming pool twice, how many meters did he run in total?
一个正方形游泳池，它的边长是9米，小明绕着游泳池跑了两圈，共跑了多少米？
<gadget id="calculator">9 * 4 * 2</gadget>
<output>72</output>

<result>72</result>