East Coast of South America ≠ Brazil

The East Coast of South America spans the entire Atlantic shoreline of the continent—from the Caribbean coast of Colombia/Venezuela/Guyana/Suriname/French Guiana, across Brazil's 7,400 km coastline, to Uruguay, Argentina, and the Strait of Magellan.

Brazil occupies the majority (~60%) of this coastline, but the term encompasses multiple sovereign nations. Equating the two is like saying "U.S. East Coast = Florida."