What was the  triangular trade? which countries did it involve? what goods were exchanged?

The best-known triangular trading system is the transatlantic slave trade, that operated from the late 16th to early 19th centuries, carrying slaves, cash crops, and manufactured goods between West Africa, Caribbean or American colonies and the European colonial powers, with the northern colonies of British North 

The early phase of the civilization lasted from circa 3300 BC until 2800 BC. This saw farming settlements grow into large and sophisticated urban centres. The quality of municipal town planning indicates that these communities were controlled by efficient governments. These clearly placed a high priority on accessibility to water. Modern scholars tend to see in this the influence of a religion which places a string emphasis on ritual washing - much like modern Hinduism. Hygiene was also important to the inhabitants. The urban planning included the world's first known urban sanitation systems. Within the city, people obtained water from wells. Within their homes, some rooms had facilities in which waste water was directed to covered drains. These lined the major streets. These ancient Indus sewerage and drainage systems were far in advance of anything found in contemporary urban sites in the Middle East. The advanced architecture and construction techniques of the Indus cities is shown by their impressive dockyards, granaries, warehouses, brick platforms, and protective walls. Their massive walls were probably designed to protect them as much from floods as from attack. Most city dwellers were traders or artisans. They lived with others of the same occupation in well-defined neighbourhoods. Although some houses were larger than others, Indus civilization cities do not show the kind of massive gulf between wealthy and poor dwellings that is found in those of other civilizations. Their society seems to have been egalitarian to a remarkable degree - but perhaps we should not make too much of this until the civilization in understood more, as this seems to contradict so much of what we know about other ancient societies. However, all the houses had access to water and drainage facilities, which gives the impression of a society where even the poor had a decent standard of living (though there may have been extensive "shanty towns" outside the walls, which have left scant archaeological remains). http://www.timemaps.com/civilization/Indus-Valley-civilization :) All that info will Help u