The shape of a forest is trapezoidal, its upper base is 36 meters, its lower base is 104 meters, and its height is 50 meters. If each tree covers an area of 25 square meters, how many trees are there in this forest?
一片树林的形状是梯形，它的上底是36米，下底是104米，高是50米．如果每棵树占地25平方米，这片树林一共有多少棵树．
<gadget id="calculator">36 + 104</gadget>
<output>140</output>

<gadget id="calculator">50 / 2 / 25</gadget>
<output>1</output>

<gadget id="calculator">140 * 1</gadget>
<output>140</output>

<result>140</result>