diff --git a/binary_search_tree/tree.py b/binary_search_tree/tree.py
index cdd5abc..b7a71ef 100644
--- a/binary_search_tree/tree.py
+++ b/binary_search_tree/tree.py
@@ -1,48 +1,115 @@
-class TreeNode:
-    def __init__(self, key, val = None):
-        if val == None:
-            val = key
+
+class TreeNode: 
+    def __init__(self, key, value = None):
+        if value == None:
+            value = key
 
         self.key = key
-        self.value = val
+        self.value = value
         self.left = None
         self.right = None
-        
-
 
 class Tree:
     def __init__(self):
         self.root = None
+    
+    def add_helper(self, current, key, value):
+        if not current:
+            return TreeNode(key,value)
+        if key <= current.key:
+            current.left = self.add_helper(current.left,key,value)
+        else:
+            current.right = self.add_helper(current.right,key,value)
+        return current
 
-    # Time Complexity: 
-    # Space Complexity: 
+
+    # Time Complexity: O(log n)
+    # Space Complexity: O(log n)
     def add(self, key, value = None):
-        pass
+        if self.root == None:
+            self.root = TreeNode(key,value)
+        else:
+            self.add_helper(self.root, key,value)
 
-    # Time Complexity: 
-    # Space Complexity: 
+        
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)
     def find(self, key):
-        pass
-
-    # Time Complexity: 
-    # Space Complexity: 
+        current = self.root
+        while current != None:
+            if current.key == key:
+                return current.value
+            elif key < current.key:
+                current = current.left
+            else:
+                current = current.right
+        return None
+        
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)
     def inorder(self):
-        pass
+        tree_nodes = []
+        return self.inorder_helper(self.root, tree_nodes)
+
+    def inorder_helper(self, root, tree_nodes):
+        if root:
+            self.inorder_helper(root.left, tree_nodes)
+            tree_nodes.append({
+                "key":root.key,
+                "value":root.value
+            })
+            self.inorder_helper(root.right, tree_nodes)
+        return tree_nodes
+
 
-    # Time Complexity: 
-    # Space Complexity:     
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)    
     def preorder(self):
-        pass
+        tree_nodes = []
+        return self.preorder_helper(self.root, tree_nodes)
+
+    def preorder_helper(self, root, tree_nodes):
+        if root:
+            tree_nodes.append({
+                "key":root.key,
+                "value":root.value
+            })
+            self.preorder_helper(root.left, tree_nodes)
+            self.preorder_helper(root.right, tree_nodes)
+        return tree_nodes
+
 
-    # Time Complexity: 
-    # Space Complexity:     
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)    
     def postorder(self):
-        pass
+        tree_nodes = []
+        return self.postorder_helper(self.root, tree_nodes)
+
+    def postorder_helper(self, root, tree_nodes):
+        if root:
+            self.postorder_helper(root.left, tree_nodes)
+            self.postorder_helper(root.right, tree_nodes)
+            tree_nodes.append({
+                "key":root.key,
+                "value":root.value
+            })
+        return tree_nodes
 
-    # Time Complexity: 
-    # Space Complexity:     
+    # Time Complexity: O(n)
+    # Space Complexity: O(h)    
     def height(self):
-        pass
+        return self.height_helper(self.root)
+    
+    def height_helper(self, current):
+        if not current:
+            return 0
+
+        left = self.height_helper(current.left)
+        right = self.height_helper(current.right)
+        return max(left, right)+1
+
+        
 
 
 #   # Optional Method
@@ -57,3 +124,5 @@ def bfs(self):
 #   # Useful for printing
     def to_s(self):
         return f"{self.inorder()}"
+
+