Two triangles and a parallelogram have equal bases and equal areas. The height of the parallelogram is 3 cm, what is the height of the triangle in cm.
两个三角形与一个平行四边形的底相等，面积也相等．平行四边形的高是3厘米，三角形的高是多少厘米．
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>