Answer:
GDP is measured by taking the quantities of all goods and services produced, multiplying them by their prices, and summing the total. GDP can be measured either by the sum of what is purchased in the economy or by what is produced. Demand can be divided into consumption, investment, government, exports, and imports.
The business cycle model shows how a nation's real GDP fluctuates over time, going through phases as aggregate output increases and decreases. Over the long-run, the business cycle shows a steady increase in potential output in a growing economy.