A vegetable field is trapezoidal, with an upper base of 400 meters, a lower base of 650 meters, and a height of 75.4 meters. How many hectares does this land cover?
一块菜地是梯形，上底是400米，下底是650米，高是75.4米，这块地合多少公顷？
<gadget id="calculator">75.2 / 2 / 10_000</gadget>
<output>0.00376</output>

<gadget id="calculator">1_050 * 0.00376</gadget>
<output>3.948</output>

<result>3.948</result>