Put up colorful flags every 3 meters around the circular playground, a total of 80 flags are inserted, what is the circumference of the circular playground in meters?
在圆形操场的四周每隔3米插上彩旗，共插上80面，这个圆形操场的周长是多少米．
<gadget id="calculator">80 * 3</gadget>
<output>240</output>

<result>240</result>