1.  To study population of any country people use population pyramid.

2. With the help of population pyramid, age wise and gender-wise population of the country can be studied.

3. Age structure and sex ratio are important aspects of population of the country.

4. In population pyramid, percentage of population in age groups are shown on the X axis. Whereas markings of age groups are shown on the Y-axis.

5. The right side of the pyramid shows female population and left side shows male population.

6. As the age groups are on Y-axis, the base of pyramid indicates young age population, and apex of pyramid indicates old age population and middle portion of pyramid indicated adult population.

7. When old age population is more, it leads to more non-working population and there is increased expenditure on medical and health facilities.

8. When younger age population is more, it also leads to more non-working and dependent population. This causes a burden on the economy.

9. When adult age population is more, then working population is more. This helps the development of the country.

10. The population pyramid makes us understand age-wise and sex-wise population as per following:

Broader the base, more young age population.

Narrower the base less young age population.

Broader the apex, more old age population.

Narrower the apex, less old age population.

Left and right side of pyramid shows male and female population in the country.

11. There are three types of population pyramids which depicts the birth rate and death rate.

• Expansive pyramid- It has abroad base and narrow apex. It shows high birth rate and high death rate.
• Constrictive pyramid- It has narrow base and broad apex. It shows low birth rate and low death rate.
• Stationary pyramid- Here all age groups have same percentage. It shows very low birth rate and very low death rate, that means slow growth of population in the country.