The sum of the upper and lower bases of a trapezoid is 14 meters, and the height is 7 meters. What is the area of the trapezoid?
一个梯形的上底与下底的和是14米，高是7米，这个梯形的面积是多少．
<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">14 * (7/2)</gadget>
<output>49</output>

<result>49</result>