The sum of the upper and lower bases of a trapezoid is 2.8 meters, and the height is 1.5 meters. What is the area?
一个梯形的上下底之和是2.8米，高是1.5米，面积是多少．
<gadget id="calculator">1.5 / 2</gadget>
<output>0.75</output>

<gadget id="calculator">2.8 * 0.75</gadget>
<output>2.1</output>

<result>2.1</result>