Geometric representation of age structure is a characteristic of population. It refers to the graphical representation of the number of individuals of different ages in a population. This information is typically presented in the form of an age pyramid or age distribution graph.

Explanation:
Age structure is an important demographic characteristic of a population that provides information about the distribution of individuals across different age groups. The age structure of a population can have significant impacts on its social, economic, and environmental characteristics. For example, a population with a high proportion of young individuals may have a higher birth rate and greater potential for economic growth, while a population with a high proportion of elderly individuals may have higher healthcare costs and a lower labor force participation rate.

Geometric representation of age structure is typically presented in the form of an age pyramid or age distribution graph. An age pyramid is a graphical representation of the number of individuals of different ages in a population, with the youngest age group at the bottom and the oldest age group at the top. The shape of the age pyramid can provide information about the historical and current trends in population growth, mortality, and fertility rates. For example, a population with a broad base and narrow top may indicate high fertility rates and a potential for future population growth, while a population with a narrow base and broad top may indicate low fertility rates and an aging population.

In conclusion, the geometric representation of age structure is an important characteristic of population that can provide valuable insights into its demographic, social, and economic characteristics.