A triangle and a parallelogram have the same height and the same area. The base of the parallelogram is 5 decimeters, what is the base of the triangle.
一个三角形和一个平行四边形的高相等，面积也相等．平行四边形的底是5分米，三角形的底是多少分米．
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>