Two sets of opposite sides are parallelogram respectively called parallelogram (parallelogram). parallelogram uses the name of the graph plus the names of the four vertices in sequence.

parallelogram perimeter can be multiplied in two (base 1+ base 2); If "a" represents base 1, "b" represents base 2, and "c parallel" represents parallelogram perimeter, then parallel perimeter c=2(a+b)