Define: i) Cyclic Graph ii) Siblings iii) Strictly Binary Tree
                            
                        
                    
                    
                        
        
            - Cyclic Graph
- A cyclic graph is a graph containing at least one graph cycle.  
- Sibling
- Siblings are nodes that share the same parent node.
- Strictly binary tree
- A strictly binary tree (sometimes proper binary tree or 2-tree or full binary tree) is a tree in which every node other than the leaves has two children.