The Triple Alliance was a secret agreement between Germany, Austria-Hungary, and Italy. It was formed on 20 May 1882 and renewed periodically until it expired in 1915 during World War I. Germany and Austria-Hungary had been closely allied since 1879. Italy sought support against France shortly after it lost North African ambitions to the French. Each member promised mutual support in the event of an attack by any other great power. The treaty provided that Germany and Austria-Hungary were to assist Italy if it was attacked by France without provocation. In turn, Italy would assist Germany if attacked by France. In the event of a war between Austria-Hungary and Russia, Italy promised to remain neutral.

Answer this question based on the passage: which country eventually joined the triple alliance with germany and austria-hungary? Let's have some stream of consciousness first.
This is the relevant information: The Triple Alliance was a secret agreement between Germany, Austria-Hungary, and Italy. So, the answer is Italy.