In a circular flowerbed, a potted flower is placed every 3 meters, and there are 12 potted flowers in total. What is the circumference of the flowerbed in meters?
一个圆形花圃，每隔3米放一盆花，一共放了12盆花，花圃周长是多少米．
<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<result>36</result>