The area of a trapezoid is 52 square centimeters, the upper base is 4 cm, and the lower base is 9 cm. What is the height of the trapezoid in cm?
一个梯形的面积是52平方厘米，上底是4厘米，下底是9厘米，那么这个梯形的高是多少厘米．
<gadget id="calculator">4 + 9</gadget>
<output>13</output>

<gadget id="calculator">2 / 13</gadget>
<output>2/13 = around 0.153846</output>

<gadget id="calculator">52 * (2/13)</gadget>
<output>8</output>

<result>8</result>