Use two identical triangles to form a parallelogram. The base of the parallelogram is 8cm and the height is 5cm. What is the area of one of the triangles in cm**2.
用两个完全一样的三角形拼成一个平行四边形，拼成的平行四边形的底是8cm，高是5cm，其中一个三角形的面积是多少cm**2．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">8 * (5/2)</gadget>
<output>20</output>

<result>20</result>