This is a Java Program to find the area of a polygon using slicker method. The algorithm assumes the usual mathematical convention that positive y points upwards. In computer systems where positive y is downwards (most of them) the easiest thing to do is list the vertices counter-clockwise using the “positive y down” coordinates. The two effects then cancel out to produce a positive area.

Here is the source code of the Java Program to Implement Slicker Algorithm that avoids Triangulation to Find Area of a Polygon. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

`//This is a java program to find the area of polygon using Slicker algorithm`

import java.util.*;

`class Area_polygon_Slicker`

`{`

static final int MAXPOLY = 200;

static final double EPSILON = 0.000001;

static class Point

`{`

double x, y;

`}`

static class Polygon

`{`

Point p[] = new Point[MAXPOLY];

int n;

Polygon()

`{`

for (int i = 0; i < MAXPOLY; i++)

p[i] = new Point();

`}`

`}`

static double area(Polygon p)

`{`

double total = 0;

for (int i = 0; i < p.n; i++)

`{`

int j = (i + 1) % p.n;

total += (p.p[i].x * p.p[j].y) - (p.p[j].x * p.p[i].y);

`}`

return total / 2;

`}`

static public void main(String[] args)

`{`

Polygon p = new Polygon();

Scanner sc = new Scanner(System.in);

System.out.println("Enter the number of points in Polygon: ");

p.n = sc.nextInt();

System.out.println("Enter the coordinates of each point: <x> <y>");

for (int i = 0; i < p.n; i++)

`{`

p.p[i].x = sc.nextDouble();

p.p[i].y = sc.nextDouble();

`}`

double area = area(p);

if (area > 0)

System.out.print("The Area of Polygon with " + p.n

+ " points using Slicker Algorithm is : " + area);

`else`

System.out.print("The Area of Polygon with " + p.n

+ " points using Slicker Algorithm is : " + (area * -1));

sc.close();

`}`

`}`

Output:

$ javac Area_polygon_Slicker.java $ java Area_polygon_Slicker Enter the number of points in Polygon: 4 Enter the coordinates of each point: <x> <y> 1 1 1 6 6 6 6 1 The Area of Polygon with 4 points using Slicker Algorithm is : 25.0 Enter the number of points in Polygon: 5 Enter the coordinates of each point: <x> <y> 1 2 4 5 9 8 3 2 1 5 The Area of Polygon with 5points using Slicker Algorithm is : 6.0

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