Final answer:
The Amazon River is the large river in Brazil that flows east into the Atlantic Ocean, known for its vast size, extensive network of tributaries, and significant discharge volume.
Step-by-step explanation:
The large river in Brazil that flows east into the Atlantic Ocean is the Amazon River. Spanning over 2,000 miles, it is often compared to the Nile in terms of length and is known for having the greatest discharge of any river in the world, carrying approximately one-fifth of the world's river water.
The Amazon's many tributaries, including the Rio Negro, the Madeira, and the Xingu, contribute to its immense volume of water, making it a vital waterway for South America. Its extended network of over 1,100 tributaries makes it an essential part of the continent's ecosystem.
The Amazon River provides an important transportation route, facilitating access to international markets from South American port cities like Iquitos.