The upper base of a trapezoid is 2 decimeters, the lower base is 5 decimeters, and the height is 4 decimeters. What is the area in square decimeters?
一个梯形的上底是2分米，下底是5分米，高是4分米，面积是多少平方分米？
<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<result>14</result>