The cross section of a barrage is trapezoidal, its area is 720 square meters, its upper base is 120 meters, and its lower base is 180 meters. How many meters is the height of this barrage?
一个拦河坝的横截面是个梯形，它的面积是720平方米，它的上底是120米，下底是180米，这个拦河坝的高度是多少米？
<gadget id="calculator">120 + 180</gadget>
<output>300</output>

<gadget id="calculator">2 / 300</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">720 * (1/150)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>