The area of a parallelogram is equal to the area of a triangle, and the height is also equal. The base of the triangle is 20cm. What is the base of the parallelogram in cm?
一个平行四边形的面积和一个三角形的面积相等，高也相等，三角形的底是20cm，平行四边形的底是多少cm．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>