Sub Equation()
Dim i As Integer
Dim LastLig As Long
LastLig = Range("C1").End(xlDown).Row
For i = 2 To LastLig
Range("E" & i).FormulaR1C1 = "=SUM(SQRT((R[" & i & "]C[3]-R[" & i & "]C[1])^2+(R[" & i & "]C[4]-R[" & i & "]C[2])^2)),SQRT((R[" & i & "]C[3]-R[" & i & +1"]C[1])^2+(R[" & i & "]C[4]-R[" & i & +1"]C[2])^2), SQRT((R[" & i & "]C[3]-R[" & i & +2"]C[1])^2+(R[ " & i & "]C[4]-R[" & i & +2"]C[2])^2)))"
Next
End Sub