Polygon area calculation using Latitude and Longitude generated from Cartesian space and a world file

Question

Given a series of GPS coordinate pairs, I need to calculate the area of a polygon (n-gon). This is relatively small (not larger than 50,000 sqft). The geocodes are created

Answer 1

Thank you Risky Pathak!

In the spirit of sharing, here's my adaptation in Delphi:

interface

uses 
  System.Math; 

TMapGeoPoint = record
  Latitude: Double;
  Longitude: Double;
end;


function AreaInAcres(AGeoPoints: TList): Double;

implementation

function AreaInAcres(AGeoPoints: TList): Double;
var
  Area: Double;
  i: Integer;
  P1, P2: TMapGeoPoint;
begin
 Area := 0;

 // We need at least 2 points
 if (AGeoPoints.Count > 2) then
 begin
   for I := 0 to AGeoPoints.Count - 1 do
   begin
     P1 := AGeoPoints[i];
     if i < AGeoPoints.Count - 1  then
       P2 := AGeoPoints[i + 1]
     else
       P2 := AGeoPoints[0];
     Area := Area + DegToRad(P2.Longitude - P1.Longitude) * (2 + 
        Sin(DegToRad(P1.Latitude)) + Sin(DegToRad(P2.Latitude)));
    end;

    Area := Area * 6378137 * 6378137 / 2;

  end;

  Area := Abs(Area); //Area (in sq meters)

  // 1 Square Meter = 0.000247105 Acres
  result := Area * 0.000247105;
end;