diff --git a/binary_search_tree/tree.py b/binary_search_tree/tree.py
index cdd5abc..7f0fbd2 100644
--- a/binary_search_tree/tree.py
+++ b/binary_search_tree/tree.py
@@ -14,36 +14,135 @@ class Tree:
     def __init__(self):
         self.root = None
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: O(log(n))
+    # Space Complexity: O(1)
     def add(self, key, value = None):
-        pass
+        added_node = TreeNode(key, value)
+        if not self.root:
+            self.root = added_node
+            return self.root
+        parent_node = self.root
+        while True:
+            # if the added_node is greater than the parent_node
+            if added_node.key > parent_node.key:
+                # if the parent_node does NOT have a right node
+                if not parent_node.right:
+                    parent_node.right = added_node
+                    return added_node
+                # if the parent_node DOES have a right node, make its right node the new parent_node 
+                else:
+                    parent_node = parent_node.right
+            # if the added_node is less than the parent_node                
+            elif added_node.key <= parent_node.key:
+                # if the parent_node does NOT have a left node
+                if not parent_node.left:
+                    parent_node.left = added_node
+                    return added_node
+                # if the parent_node DOES have a left node, make its left node the new parent_node
+                else:
+                    parent_node = parent_node.left
+            else:
+                return "WTF"
+                    
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: O(log(n))
+    # Space Complexity: O(1)
     def find(self, key):
-        pass
+        current_node = self.root
+        while current_node:
+            if key == current_node.key:
+                return current_node.value
+            elif key > current_node.key:
+                current_node = current_node.right
+            elif key < current_node.key:
+                current_node = current_node.left
+        return None
+
+    # left, current, right
+    def inorder_helper(self, current_node, node_list = None):
+        if node_list == None:
+            node_list = []
+        if current_node:
+            self.inorder_helper(current_node.left, node_list)
+            node_list.append({
+                "key" : current_node.key,
+                "value" : current_node.value,
+            })
+            self.inorder_helper(current_node.right, node_list)
+        return node_list
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)
     def inorder(self):
-        pass
+        return self.inorder_helper(self.root)
+
+    def preorder_helper(self, current_node, node_list = None):
+        if node_list == None:
+            node_list = []
+        if current_node:
+            node_list.append({
+                "key" : current_node.key,
+                "value" : current_node.value,
+            })
+            self.preorder_helper(current_node.left, node_list)
+            self.preorder_helper(current_node.right, node_list)
+        return node_list
 
-    # Time Complexity: 
-    # Space Complexity:     
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)  
     def preorder(self):
-        pass
+        return self.preorder_helper(self.root)
 
-    # Time Complexity: 
-    # Space Complexity:     
+    def postorder_helper(self, current_node, node_list = None):
+        if node_list == None:
+            node_list = []
+        if current_node:
+            self.postorder_helper(current_node.left, node_list)
+            self.postorder_helper(current_node.right, node_list)
+            node_list.append({
+                "key" : current_node.key,
+                "value" : current_node.value,
+            })
+        return node_list
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)  
     def postorder(self):
-        pass
+        return self.postorder_helper(self.root)
 
-    # Time Complexity: 
-    # Space Complexity:     
-    def height(self):
-        pass
+    def height_helper(self, current_node, node_list = None):
+        if node_list == None:
+            node_list = []
+        if current_node:
+            self.height_helper(current_node.left, node_list)
+            if current_node.left == None and current_node.right == None:
+                node_list.append(current_node.key)
+            self.height_helper(current_node.right, node_list)
+        return node_list
+    
+    def find_count(self, key):
+        current_node = self.root
+        count = 0
+        while current_node:
+            count += 1
+            if key == current_node.key:
+                return count
+            elif key > current_node.key:
+                current_node = current_node.right
+            elif key < current_node.key:
+                current_node = current_node.left
+        return None
 
+    # Time Complexity: O(nlog(n))
+    # Space Complexity: O(m) where m is the number of end nodes  
+    def height(self):
+        ends_list = self.height_helper(self.root)
+        max_height = 0
+        for end_key in ends_list:
+            height = self.find_count(end_key)
+            if height > max_height:
+                max_height = height
+        return max_height
 
 #   # Optional Method
 #   # Time Complexity: