The area of a trapezoid is 740m**2. It is known that the upper base is 38m and the height of the trapezoid is 20m. What is the lower base of the trapezoid in m?
一个梯形面积740m**2，已知上底38m，梯形高20m，这个梯形下底是多少m．
<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">740 * (1/10)</gadget>
<output>74</output>

<gadget id="calculator">74 - 38</gadget>
<output>36</output>

<result>36</result>