It is known that the sum of the upper and lower bases of the trapezoid is 40 meters, the area is 100 square meters, and what is the height.
已知梯形的上底和下底的和40米，面积是100平方米，高是多少．
<gadget id="calculator">2 / 40</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">100 * (1/20)</gadget>
<output>5</output>

<result>5</result>