The area of a trapezoid is 0.81m**2, and the height is 0.9m. What is the sum of the upper and lower bases of the trapezoid in m?
一个梯形的面积是0.81m**2，高是0.9m，这个梯形上底与下底的和是多少m．
<gadget id="calculator">2 / 0.9</gadget>
<output>2.222222</output>

<gadget id="calculator">0.81 * 2.222222</gadget>
<output>1.8</output>

<result>1.8</result>