Final answer:
The Triple Alliance originally included Germany, Austria-Hungary, and Italy. The Triple Entente opposed them, consisting of France, Great Britain, and Russia. Italy switched to join the Triple Entente in 1915, and the United States joined in 1917.
Step-by-step explanation:
The members of the Triple Alliance were Germany, Austria-Hungary, and initially Italy. This alliance was formed as part of the pre-World War I central European powers. However, it's important to note that Italy eventually switched sides to join the Triple Entente in 1915. The Central Powers, an expanded group that included the Triple Alliance members, came to also include the Ottoman Empire.
The Triple Entente, the opposing alliance of the Triple Alliance, was comprised of France, Great Britain, and Russia. These alliances played a crucial role in the formation of sides during World War I and the resulting global conflict. The United States later joined the Triple Entente allies in 1917.