The area of a parallelogram is 84 square decimeters, what is the area of a triangle with the same base and height as dm**2.
一个平行四边形的面积是84平方分米，和它等底等高的三角形面积是多少dm**2．
<gadget id="calculator">84 / 2</gadget>
<output>42</output>

<result>42</result>