Requirement
- Write a program that enters 3 points in the plane as integer x and y coordinates
- Calculates and prints the area of the triangle composed by these 3 points.
- Round the result to a whole number.
- In case the three points do not form a triangle, print "0" as result.
Demo
public class Main {
public static void main(String[] args) {
int x1 = 1;// ww w .j a v a 2s .com
int y1 = 2;
int x2 = 3;
int y2 = 4;
int x3 = 5;
int y3 = 6;
// find the distance between three points (sides of triangle)
double aSide = Math.sqrt(Math.pow(x3 - x2, 2) + Math.pow(y3 - y2, 2));
double bSide = Math.sqrt(Math.pow(x1 - x3, 2) + Math.pow(y1 - y3, 2));
double cSide = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
double halfPerimeter = (aSide + bSide + cSide) / 2;
double triangleArea = Math
.sqrt(halfPerimeter * (halfPerimeter - aSide) * (halfPerimeter - bSide) * (halfPerimeter - cSide));
System.out.printf("%.0f\n", triangleArea);
}
}