(Time to break out your geometry sets J)
BIG IDEAS
Know how to Construct Circles:
BIG IDEAS
Know how to Construct Circles:
- distance all the way across the center circle is called the diameter
- distance from the center of the circle to the edge (halfway across) is called the radius
- to make a nice, even circle - use a string or a compass set to the radius amount
- < > is the distance around the outside edge (or perimeter of the circle)Approximately 3 times the diameter
- Calculated by PI MULTIPLIED BY DIAMETER (pd)
- Calculated by 2 MULTIPLIED BY PI MULTIPLIED BY THE RADUIS (2pr)
- < > is a constant ( a number that is always the same value), we round it to 3.14The 2D (flat) space that a shape takes up
- Measured in squared units (cm2, m2, feet2, etc)
- Calculated by pr2
(p x r x r) - Remember - radius is half the length of the diameter
- Represent info comparing parts to the whole by using percentage or fractions of a circle
- Need to have 100% total
- Circle is divided into sectors, easier to read when not too many of them or too small of percentages.
- Need to first know the total, and use that to make your categories into percentages
- Change each percentage into a decimal
- Use the decimals to find the correct angles (by multiplying by 360, out of a total 360 degrees)
- Use a protractor to measure the angle and place it on your circle graph (this takes some additional steps and practice)
- Can also use technology (spreadsheets, tables, etc.)