The upper base of a trapezoidal paddy field is 120 meters, the lower base is 60 meters longer than the upper base, and the height is 20 meters. If 4,000 kilograms of rice can be harvested per hectare, how much rice can be harvested on this land?
一块梯形稻田的上底为120米，下底比上底长60米，高20米．如果每公顷地可以收稻谷4000千克，这块地一共可以收稻谷多少？
<gadget id="calculator">120 + 120 + 60</gadget>
<output>300</output>

<gadget id="calculator">20 / 2 / 10_000</gadget>
<output>1/1_000 = around 0.001</output>

<gadget id="calculator">300 * (1/1_000) * 4_000</gadget>
<output>1_200</output>

<result>1_200</result>