The base of a parallelogram is 8.5dm and the height is 4dm. What is the area of the triangle with the same base and height?
一个平行四边形的底是8.5dm，高是4dm，与它等底等高的三角形的面积是多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">8.5 * 2</gadget>
<output>17</output>

<result>17</result>