A triangle and a parallelogram have the same area and the same base. If the height of the parallelogram is 18 cm, what is the height of the triangle in cm?
一个三角形和一个平行四边形面积相等，底也相等．如果平行四边形的高是18厘米，三角形的高就是多少厘米．
<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<result>36</result>