There is a vegetable field in the shape of a trapezoid, the upper base is 13 meters, the lower base is 22 meters, and the height is 50 meters. What is the area of this vegetable field in square meters?
有一块菜地为梯形，上底是13米，下底22米，高是50米，这块菜地的面积是多少平方米？
<gadget id="calculator">13 + 22</gadget>
<output>35</output>

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

<gadget id="calculator">35 * 25</gadget>
<output>875</output>

<result>875</result>