The difference in length between the upper and lower bases of a trapezoid is 5 cm, the lower base is 1.5 times the upper base, and the height is 2 cm. Find the area of the trapezoid.
梯形上、下底的长度相差5厘米，下底是上底的1.5倍，高是2厘米．求梯形的面积．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">5 * 1</gadget>
<output>5</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<result>15</result>