The height and area of a triangle and a parallelogram are equal, the base of the triangle is 30cm, what is the base of the parallelogram in centimeters.
一个三角形和一个平行四边形的高和面积都相等，三角形的底是30cm，平行四边形的底是多少厘米．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<result>15</result>