在一个周长为270米的圆形场地周围每隔18米竖一面彩旗，需要多少面彩旗？1Y0W1_+Q;U)f
算式：提示0{:z2\7~-Z2Z*J1M0`1Y0W1_+Q;U)f
答：需要,@.O2T0H1w0G1u面彩旗。1Y0W1_+Q;U)f