The sum of the upper and lower bases of a trapezoid is 16 cm and the height is 7 cm. What is the area of the trapezoid in square centimeters?
一个梯形，上下底的和是16厘米，高是7厘米，这个梯形的面积是多少平方厘米．
<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">16 * (7/2)</gadget>
<output>56</output>

<result>56</result>