For an approximate trapezoidal orchard, the sum of the upper base and the lower base is 500 meters, and the height is 60 meters. Calculated by spraying 0.9 kilograms of pesticides per hectare, how many kilograms of pesticides are needed to spray this orchard once?
一个近似的梯形果园，上底加下底的和是500米，高60米，按每公顷喷洒农药0.9千克计算，给这个果园喷洒一次农药，一共需要多少千克农药？
<gadget id="calculator">60 / 2 / 10_000</gadget>
<output>3/1_000 = around 0.003</output>

<gadget id="calculator">500 * (3/1_000) * 0.9</gadget>
<output>1.35</output>

<result>1.35</result>