The area of the triangle and the parallelogram are equal, and their bases are also equal. If the height of the triangle is 30cm, what is the height of the parallelogram?
三角形和平行四边形的面积相等，而且它们的底也相等，如果三角形的高30cm，那么平行四边形的高是多少．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<result>15</result>