If you plant fir trees on a square land with a circumference of 1200 meters, how many fir trees can be planted on this land based on the calculation of 250 trees per hectare?
在一块周长是1200米的正方形土地上种杉树，按每公顷250棵计算，这块地一共可以种多少棵杉树？
<gadget id="calculator">900_000 / 10_000</gadget>
<output>90</output>

<gadget id="calculator">90 * 250</gadget>
<output>22_500</output>

<result>22_500</result>