java编程题目求三角形的面积的答案

liang183

package nameyu;import java.util.Scanner;public class Test {

    /**

     * @param args

     */

    public static void main(String[] args) {

        // TODO Auto-generated method stub

        Scanner input=new Scanner(System.in);

        System.out.println("Enter three points for a triangle :");

        double x1=input.nextDouble();

        double y1=input.nextDouble();

        double x2=input.nextDouble();

        double y2=input.nextDouble();

        double x3=input.nextDouble();

        double y3=input.nextDouble();

        double s1=Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));

        double s2=Math.sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));

        double s3=Math.sqrt((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2));

        double s=(s1+s2+s3)/2;

        double area=Math.sqrt(s*(s-s1)*(s-s2)*(s-s3));

        System.out.println("The area of the triangle is "+(int)(area*10)/10.0);

    }

}