The sum of the upper and lower bases of a trapezoid is 15 meters and the height is 8 meters. What is the area of the trapezoid in square meters?
一个梯形上、下底之和是15米，高是8米，这个梯形的面积是多少平方米．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<result>60</result>