Page-1 Parallelogram Sheet.28 Sheet.29 Sheet.33 Sheet.36 Sheet.37 Sheet.38 X X Sheet.43 X1 X1 Sheet.52 X2 X2 Sheet.53 Y Y Sheet.54 Xr = X + α(X1 – X) + β(X2 – X) Xr = X + α(X1 – X) + β(X2 – X)