Check now working for all kinds of triangles.

Including Tests for all Checks.

.idea/libraries/jars.xml

+<component name="libraryTable">
+  <library name="jars">
+    <CLASSES>
+      <root url="jar://$PROJECT_DIR$/jars/hamcrest-core-1.3.jar!/" />
+      <root url="jar://$PROJECT_DIR$/jars/junit-4.12.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/misc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" project-jdk-name="openjdk-17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/TriangleCheckerAssignment.iml" filepath="$PROJECT_DIR$/TriangleCheckerAssignment.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

TriangleCheckerAssignment.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="jars" level="project" />
+  </component>
+</module>

src/TriangleChecker.java

+import java.util.Arrays;
 import java.util.Scanner;
 
 public class TriangleChecker {
-  
-  public enum TriangleType {
-    NONE, 
-    NORMAL,
-    ISOSCELES,  // Gleichschenklig
-    EQUILATERAL // Gleichseitig
-  }
-
-
-  public static void main(String[] args) {
-    Scanner s = new Scanner(System.in);
-    System.out.println("Geben Sie die Seitenlängen ein.");
-    float a = enterFloat(s, "a: ");
-    float b = enterFloat(s, "b: ");
-    float c = enterFloat(s, "c: ");
-    s.close();
-    printAnalysis(a, b, c);
-  }
-
-  // Eingabe einer Seitenlänge
-  private static float enterFloat(Scanner s, String prompt) {
-    System.out.print(prompt);
-    return s.nextFloat();
-  }
-
-  // Ausgabe der ermittelten Dreiecksart
-  private static void printAnalysis(float a, float b, float c) {
-    TriangleType type = checkTriangle(a, b, c);
-    switch (type) {
-      case NONE:
-        System.out.println("Kein Dreieck");
-        break;        
-      case NORMAL:
-        System.out.println("Dreieck");
-        break;        
-      case ISOSCELES:
-        System.out.println("Gleichschenkliges Dreieck");
-        break;        
-      case EQUILATERAL:
-        System.out.println("Gleichseitiges Dreieck");
-        break;        
+
+    public enum TriangleType {
+        NONE,
+        NORMAL,
+        ISOSCELES,  // Gleichschenklig
+        EQUILATERAL // Gleichseitig
+    }
+
+
+    public static void main(String[] args) {
+        Scanner s = new Scanner(System.in);
+        System.out.println("Geben Sie die Seitenlängen ein.");
+        float a = enterFloat(s, "a: ");
+        float b = enterFloat(s, "b: ");
+        float c = enterFloat(s, "c: ");
+        s.close();
+        printAnalysis(a, b, c);
+    }
+
+    // Eingabe einer Seitenlänge
+    private static float enterFloat(Scanner s, String prompt) {
+        System.out.print(prompt);
+        return s.nextFloat();
+    }
+
+    // Ausgabe der ermittelten Dreiecksart
+    private static void printAnalysis(float a, float b, float c) {
+        TriangleType type = checkTriangle(a, b, c);
+        switch (type) {
+            case NONE:
+                System.out.println("Kein Dreieck");
+                break;
+            case NORMAL:
+                System.out.println("Dreieck");
+                break;
+            case ISOSCELES:
+                System.out.println("Gleichschenkliges Dreieck");
+                break;
+            case EQUILATERAL:
+                System.out.println("Gleichseitiges Dreieck");
+                break;
+        }
     }
-  }
 
-  // Analyse der Dreiecksart
-  public static TriangleType checkTriangle(float a, float b, float c) {
-    return TriangleType.NONE;
-  }
+    // Analyse der Dreiecksart
+    public static TriangleType checkTriangle(float a, float b, float c) {
+        //find Hypotenuse
+        float[] tmp = {a, b, c};
+        Arrays.sort(tmp);
+        float hypo = tmp[2];
+        float a1 = tmp[0];
+        float b1 = tmp[1];
+
+
+        //normal
+        if (a1 + b1 > hypo) {
+
+            //gleichseitig
+            if (a1 + b1 + hypo == 3 * a1)
+                return TriangleType.EQUILATERAL;
 
+            //gleichschenklig
+            if (a1 == b1 || b1 == hypo || a1 == hypo)
+                return TriangleType.ISOSCELES;
+
+            return TriangleType.NORMAL;
+
+        }
+        return TriangleType.NONE;
+    }
 
 }

test/TriangleCheckerTest.java

 import org.junit.Test;
+
+import java.util.Arrays;
+
 import static org.junit.Assert.*;
 
 public class TriangleCheckerTest {
-    
+
     @Test
     public void testValidTriangle() {
 
         assertEquals(TriangleChecker.TriangleType.NORMAL, type);
 
     }
+    @Test
+    public void testEquilateralTriangle() {
+
+        // Arrange
+        float a = 2;
+        float b = 2;
+        float c = 2;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.EQUILATERAL, type);
+    }
+    @Test
+    public void testIsocelesTriangle() {
+
+        // Arrange
+        float a = 2;
+        float b = 2;
+        float c = 3;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.ISOSCELES, type);
+    }
+    @Test
+    public void testNoTriangle() {
 
+        // Arrange
+        float a = 2;
+        float b = 2;
+        float c = 4;
+
+        // Act
+        TriangleChecker.TriangleType type = TriangleChecker.checkTriangle(a, b, c);
+
+        // Assert
+        assertEquals(TriangleChecker.TriangleType.NONE, type);
+    }
 }
+