Math 8
Notes
Circle Graphs
Name: _____________________
Date: ______ Group: __________
Given: Table of values representing a set of data
Task: Construct a circle graph to represent the data.
Steps
1. Determine the percent value of each item in the table. Check your work by
adding the percents; your sum should equal 100%.
2. Multiply each percent value by 360. This procedure will calculate the
angle measure of each color. Check your work by adding the degrees;
your sum should equal 360.
3. Mark a point on your paper (this is the center of your circle). Construct a
circle using your compass, be sure to place the point of your compass on
the center point you drew.
4. Using your straight-edge construct a radius in the circle (this will be one
side of the first angle you construct).
5. Using a protractor measure the degree measure of the first angle you are
going to construct. Mark the correct degree measurement, then use a
straight-edge to draw a radius from the center of the circle to the edge (this
is the other side of the first angle you’re constructing).
6. Repeat step 5 until all angles have been constructed. Be sure to use the
last radius you draw each time you measure another angle.
Example
Construct a circle graph to represent the data given in the table below.
Favorite Colors
Color
Purple
Blue
Yellow
Green
Red
# of People
10
15
4
8
11