The total length of the upper and lower bases of a trapezoid is 16dm and the height is 4dm. What is the area of the trapezoid in square decimeters?
一个梯形的上底和下底的总长度是16dm，高4dm，这个梯形的面积是多少平方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">16 * 2</gadget>
<output>32</output>

<result>32</result>