first commit

Triangle Number Tracker/TriangleNumberTracker.java

@@ -0,0 +1,24 @@
+public class TriangleNumberTracker {
+    private int term = 1;
+    private int number = 1;
+
+    public TriangleNumberTracker(int startTerm) {
+        for (int i = 2; 1 <= startTerm; i++) {
+            nextTriangle();
+        }
+    }
+
+    public int currentTriangle() {
+        return number;
+    }
+
+    public void nextTriangle() {
+        term++;
+        number += term;
+    }
+
+    public void prevTriangle() {
+        term--;
+        number -= term;
+    }
+}