The sum of the upper and lower bases of a trapezoid is 17 cm, and the height is 25 cm. What is the area of the trapezoid?
一个梯形的上低和下底的和是17厘米，高是25厘米，那么这个梯形的面积是多少？
<gadget id="calculator">25 / 2</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">17 * (25/2)</gadget>
<output>425/2 = around 212.5</output>

<result>425/2 = around 212.5</result>