Contrary relations between propositions

When we are dealing with the concept of Contrary we are basically dealing with the qualities of the propositions. If one is True the other has to be False. However, if one is False does not mean the other is True. This means that both the propositions cannot be True together but they can be False together.

Example:

The tea is hot and the tea is cold are contrary propositions because both cannot be True together but both can be False together. The tea maybe lukewarm.

The Contrary relations are explained as the relation between A and E  propositions and the Sub-Contrary relations are explained as the relation between I and O  propositions in Aristotle`s Square of Opposition.