A trapezoidal fish pond has an upper base of 400 meters, a width of 300 meters and a height of 200 meters. If 12,000 fish are raised per hectare of water surface, how many fish are raised in this fish pond?
一个梯形鱼塘，上底400米，宽300米，高200米．如果每公顷水面养鱼12000尾，这个鱼塘共养鱼多少尾？
<gadget id="calculator">300 + 400</gadget>
<output>700</output>

<gadget id="calculator">200 / 2 / 10_000</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">700 * (1/100) * 12_000</gadget>
<output>84_000</output>

<result>84_000</result>