The sum of the upper and lower bases of a trapezoid is 25 decimeters, and the height is 8 decimeters. What is the area of the trapezoid in square decimeters?
一个梯形的上、下底的和是25分米，高是8分米，这个梯形的面积是多少平方分米．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<result>100</result>