If a parallelogram with an area of 80 square decimeters is cut along the line connecting the vertices of the diagonals, two identical triangles can be obtained. What is the area of each triangle?
一个面积是80平方分米的平行四边形沿对角线顶点连线剪开，就可以得到两个完全一样的三角形，每个三角形的面积是多少平方分米．
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<result>40</result>