The sum of the top and bottom of a trapezoid is 12.5cm, the height is 2.5cm, what is the area?
一个梯形的上底与底的和是12.5cm，高是2.5cm，面积多少．
<gadget id="calculator">2.5 / 2</gadget>
<output>1.25</output>

<gadget id="calculator">12.5 * 1.25</gadget>
<output>15.625</output>

<result>15.625</result>