The sum of the upper and lower bases of a trapezoid is 22 meters and the height is 4 meters. What is its area in square meters?
一个梯形的上底与下底的和是22米，高4米，它的面积是多少平方米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">22 * 2</gadget>
<output>44</output>

<result>44</result>