Javaを使って、3点の座標で三角形の面積を求めます
1182 ワード
プログラムを作成し、ユーザに三角形の3つの点(x 1,y 1)、(x 2,y 2)、(x 3,y 3)を入力し、その面積を表示するように促す.
import java.util.Scanner;
public class Home04 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println(" 1 :");
double x1 = scanner.nextDouble();
double y1 = scanner.nextDouble();
System.out.println(" 2 :");
double x2 = scanner.nextDouble();
double y2 = scanner.nextDouble();
System.out.println(" 3 :");
double x3 = scanner.nextDouble();
double y3 = scanner.nextDouble();
/*
* A(x1,y1),B(x2,y2)
AB √[(X1-X2)^2+(Y1-Y2)^2]
* */
/*
* 1 2
* :Math.sqrt(double s);
* */
double first = Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
/*
* 2 3
* */
double second = Math.sqrt((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3));
/*
* 3 1
* */
double third = Math.sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));
/*
*
* */
double s = (first+second+third)/2;
double area = Math.sqrt(s*(s-first)*(s-second)*(s-third));
System.out.println("area"+area);
}
}