In order to allow the grass on the playground to grow well and make the lawn green as soon as possible, the school surrounded the playground with colorful flags and bamboo poles to surround the guardrail. There is a parallelogram lawn with a base length of 2000 cm and a height of 0.9 times the base. If the cost of maintaining a lawn of 1 square meter is 15 yuan, how much does it cost to maintain this lawn?
为了能让操场上的小草好好生长，让草坪尽快绿起来，学校在操场周围用彩旗和竹杆围起了护栏．有一块平行四边形草坪底长2000厘米，高是底的0.9倍，如果护养1平方米草坪的价格是15元，那么，养护这块草坪需多少钱？
<gadget id="calculator">2_000 / 100</gadget>
<output>20</output>

<gadget id="calculator">20 * 0.9</gadget>
<output>18</output>

<gadget id="calculator">20 * 18 * 15</gadget>
<output>5_400</output>

<result>5_400</result>