It is known that the area of a trapezoid is 18 square centimeters. Its upper base is 3.6 cm, its lower base is 5.4 cm, and its height is in cm.
已知一个梯形的面积是18平方厘米．它的上底是3.6厘米，下底是5.4厘米，高是多少厘米．
<gadget id="calculator">3.6 + 5.4</gadget>
<output>9</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">18 * (2/9)</gadget>
<output>4</output>

<result>4</result>