The area of a triangular plate is 1.4 square decimeters, what is the area of the parallelogram formed by two such triangular plates?
一块三角板的面积是1.4平方分米，用两块这样的三角板拼成的平行四边形的面积是多少．
<gadget id="calculator">1.4 * 2</gadget>
<output>2.8</output>

<result>2.8</result>