Put a pot of flowers every 3 meters on a garden-shaped flower bed, and put 15 pots of flowers in total. What is the perimeter of the flower bed in meters?
在一个园形花圃上每隔3米放一盆花，一共放了15盆花，这个花坛的周长是多少米．
<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>