which two countries are on the western border of bolivia
Bolivia It is constitutionally a unitary state, divided into nine departments. Its geography varies from the peaks of the Andes in the West, to the Eastern Lowlands, situated within the Amazon Basin. It is bordered to the north and east by Brazil, to the southeast by Paraguay, to the south by Argentina, to the southwest by Chile, and to the northwest by Peru. One-third of the country is within the Andean mountain range. With 1,098,581 km2 (424,164 sq mi) of area, Bolivia is the 5th largest country in South America and the 27th largest in the world.
Andes The Andes or Andean Mountains (Spanish: Cordillera de los Andes) are the longest continental mountain range in the world. They form a continuous highland along the western edge of South America. This range is about 7,000 km (4,300 mi) long, about 200 to 700 km (120 to 430 mi) wide (widest between 18° south and 20° south latitude), and of an average height of about 4,000 m (13,000 ft). The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Chile.