Section 3-5
Circle Graphs
A circle graph is a way to organize data using the sectors of a circle.
Example:
Suppose you take a poll of the students in your class to find out their favorite foods, and get the following results:
- Ice Cream - 24%
- Pizza - 41%
- Raw Mushrooms - 9%
- Dog Food - 11%
- Chicken Livers - 15%
Organize this data in a circle graph.
The data are given as percentages. To make the sectors the right size, you need to use the fact that there are 360 degrees in a circle, and solve some proportions. For example, to find the number of degrees in the sector for chicken livers, you need to solve:
It turns out that x = 54, so you need to measure a 54 degree sector to represent the portion of the class that loves chicken liver.
