Задание 2. Периметр и площадь треугольника

src/tse/LR_1.java

@@ -1,5 +1,7 @@
 package tse;
 
+import tse.lr1.Triangle;
+
 /**
  * @author aNNiMON
  */
@@ -13,7 +15,15 @@ public class LR_1 implements ILabRab {
 
     @Override
     public void execute(int index) {
-        System.out.println(TITLES[index]);
+        switch(index) {
+            case 0:
+                break;
+            case 1:
+                Triangle.main();
+                break;
+            case 2:
+                break;
+        }
     }
 
     @Override

src/tse/Util.java

@@ -5,6 +5,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
 
 /**
  *
@@ -39,4 +40,12 @@ public class Util {
         }
         return text.toString();
     }
+    
+    public static double readDouble(Scanner sc) {
+        while (!sc.hasNextDouble()) {
+            System.out.println("Ошибка! Неверный формат!");
+            sc.next();
+        }
+        return sc.nextDouble();
+    }
 }

src/tse/lr1/Triangle.java

@@ -0,0 +1,58 @@
+package tse.lr1;
+
+import java.awt.geom.Point2D;
+import java.util.Scanner;
+import tse.Util;
+
+/**
+ * Площадь и периметр треугольника.
+ * @author aNNiMON
+ */
+public class Triangle {
+    
+    private final Scanner scanner;
+    private Point2D pointA, pointB, pointC;
+    
+    public static void main() {
+        new Triangle().work();
+    }
+    
+    public Triangle() {
+        scanner = new Scanner(System.in);
+    }
+
+    private void work() {
+        pointA = readPoint('A');
+        pointB = readPoint('B');
+        pointC = readPoint('C');
+        double sideAB = calcSideLength(pointA, pointB);
+        double sideBC = calcSideLength(pointB, pointC);
+        double sideAC = calcSideLength(pointA, pointC);
+        
+        double perimeter = sideAB + sideBC + sideAC;
+        System.out.println("Периметр треугольника: " + perimeter);
+        
+        double p = perimeter / 2;
+        double square = Math.sqrt(p * (p - sideAB) * (p - sideBC) * (p - sideAC));
+        System.out.println("Площадь треугольника: " + square);
+    }
+    
+    private double calcSideLength(Point2D pt1, Point2D pt2) {
+        //double tempX = (pt2.getX() - pt1.getX());
+        //double tempY = (pt2.getY() - pt1.getY());
+        //return Math.sqrt(tempX * tempX + tempY * tempY);
+        return pt1.distance(pt2);
+    }
+    
+    private Point2D readPoint(char symbol) {
+        System.out.println("Введите координаты точки "+ symbol +":");
+        return readCoodinates();
+    }
+
+    private Point2D readCoodinates() {
+        double x = Util.readDouble(scanner);
+        double y = Util.readDouble(scanner);
+        return new Point2D.Double(x, y);
+    }
+    
+}