The area of a parallelogram is 31 square decimeters, what is the area of a triangle with the same base and height as it?
平行四边形的面积是31平方分米，与它等底等高的三角形的面积是多少平方分米．
<gadget id="calculator">31 / 2</gadget>
<output>31/2 = around 15.5</output>

<result>31/2 = around 15.5</result>