/*This is a Java Program to check whether a point lies inside, outside or on the circle. For any point t (xt, yt) on the plane, its position with respect to the circle defined by 3 points (x1, y1) , (x2, y2), (x3, y3). s = (x-xt)^2 + (y-yt)^2 – r*r If s < 0, t lies inside the circle; if s > 0, t lies outside the circle; if s = 0, t lies on the circle.*/ //This is a java program to check whether point d lies inside or outside the circle defined by a, b, c points import java.util.Random; import java.util.Scanner; public class Position_Point_WRT_Circle { public static void main(String args[]) { Random random = new Random(); int x1, y1, x2, y2, x3, y3; double m1, m2, c1, c2, r; x1 = random.nextInt(10); y1 = random.nextInt(10); x2 = random.nextInt(10); y2 = random.nextInt(10); x3 = random.nextInt(10); y3 = random.nextInt(10); m1 = (y1 - y2) / (x1 - x2); m2 = (y3 - y2) / (x3 - x2); c1 = ((m1 * m2 * (y3 - y1)) + (m1 * (x2 + x3)) - (m2 * (x1 + x2))) / (2 * (m1 - m2)); c2 = ((((x1 + x2) / 2) - c1) / (-1 * m1)) + ((y1 + y2) / 2); r = Math.sqrt(((x3 - c1) * (x3 - c1)) + ((y3 - c2) * (y3 - c2))); System.out.println("The points on the circle are: (" + x1 + ", " + y1 + "), (" + x2 + ", " + y2 + "), (" + x3 + ", " + y3 + ")"); System.out.println("The center of the circle is (" + c1 + ", " + c2 + ") and radius is " + r); System.out.println("Enter the point : ,"); Scanner scan = new Scanner(System.in); int x, y; x = scan.nextInt(); y = scan.nextInt(); double s = ((x - c1) * (x - c1)) + ((y - c2) * (y - c1)) - (r * r); if (s < 0) System.out.println("The point lies inside the circle"); else if (s > 0) System.out.println("The point lies outside the circle"); else System.out.println("The point lies on the circle"); scan.close(); } } /* The points on the circle are: (5, 9), (4, 7), (2, 0) The center of the circle is (34.5, 23.25) and radius is 39.960136386153636 Enter the point : , 3 5 The point lies inside the circle The points on the circle are: (0, 1), (2, 3), (5, 4) The center of the circle is (3.5, 4.5) and radius is 1.5811388300841898 Enter the point : , 1 2 The point lies outside the circle