They are popular because they are popular, which is a circular argument that suits a pie chart. But there are some serious downsides to using the humble pie.

The theory provides a guideline for graph construction: Graphs should employ elementary tasks as high in the ordering as possible. This principle is applied to a variety of graphs, including bar ...

It tests the ability to read, understand, and draw conclusions from data presented in the form of tables, bar graphs, pie charts, and line graphs.