A square square with a circumference of 60 meters is surrounded by trees, and one tree is planted every 3 meters. How many trees can be planted?
在一个周长为60米的正方形广场四周是植树，每隔3米植一棵，可植树多少棵．
<gadget id="calculator">60 / 3</gadget>
<output>20</output>

<result>20</result>