It is known that the area of a trapezoid is 58 square centimeters, its upper base is 15 cm, and its lower base is 25 cm. What is its height in cm?
已知一个梯形的面积是58平方厘米，它的上底是15厘米，下底是25厘米，它的高是多少厘米？
<gadget id="calculator">15 + 25</gadget>
<output>40</output>

<gadget id="calculator">2 / 40</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">58 * (1/20)</gadget>
<output>29/10 = around 2.9</output>

<result>29/10 = around 2.9</result>