
How to calculate area of a polygon if we have lat long of all points?



did you ever gen an answer? i have the same question.



Hi, You can not calculate area directly from lat/long.. you have to first convert or project the lat/longt to any projected coordinate system and get x , y.. Once x & y received use following function to calculate the area 
Private Function GetArea(ByVal x_y_array As ArrayList) As Single
Try
Dim area As Single
Dim TotalItm As Long = x_y_array .Count
For i As Integer = 0 To TotalItm  1
a = x_y_array .Item(i)
If i = x_y_array  1 Then b = x_y_array .Item(0) Else b = x_y_array .Item(i + 1)
area = area + _
(b.X  a.X) * _
(b.Y + a.Y) / 2
Next
GetArea= area
Catch ex As Exception
MsgBox("Error occured, Area calculation failed. " & ex.Message, 0 + 16, "Error")
GetArea= 0
Finally
End Try
End Function

