Distance between (-1,2) and (3,2) = 4
Distance between (3,2) and ( 3,7) = 5
Distance between (-1,2) and (3,7) = sqrt [ (3 - -1)^2 + ( 7 - 2)^2 ] = sqrt [ 4^2 + 5^2 ] = sqrt (41) ≈ 6.4
The estimated perimeter of the new figure is 2 [ 4 + 5 + 6.4 ] = 30.8 = 31