People who study population trends have developed a special type of bar graph to show how the population of an area is divided by age and gender. It is called a POPULATION PYRAMID.

Scroll over the image below to learn more about the parts of the population pyramid.

The information that can be derived from these bars on the graph can tell a lot about what the changes in the birth and death rates of a particular area.

Roll over the three pyramids below to learn more.

Below are some items to look for when reading a population pyramid:

• Width of the base- birth rate varies with the width of the base.
• Symmetry- pyramids should be symmetrical. Any asymmetry indicates a difference in the male and female population.
• Shape of sides- Concave sides (curving inward) indicate a high death rate and convex sides (bulging outward) indicate a low death rate.
• Bumps in the sides- irregularities in the sides indicate a demographic anomaly.