Population Pyramid

1.  A population pyramid, also called an age pyramid or age picture diagram, is a graphical illustration that shows the distribution of various age groups in a population, which forms the shape of a pyramid when the population is growing. 
2.

 3.The top picture shows a population pyramid of a developing country like angola in 2012. The bottom part shows ukraine in 2012.
4.Population pyramids are useful because they show if a population grew or died.