Let 1a1−2i,1a2−2i,1a3−2i,1a4−2i,1a5−2i,1a6−2i,1a7−2i,1a8−2i  are vertices of regular octagon. If the area of octagon is A, then the value of 82A is (where aj∈R for j=1,2,3,4,5,6,7,8  and i=−1 ) _____