11.1: Circumference and Arc Length (4/24 Notes)
Circumference: The distance around a circle.
Circumference is the same thing as...
Circumference Equations:
(r = radius)
(d = diameter)
Watch this video to see why...
Before talking about arc length...
Complete Practice #1 and #2 on page 5.
For each question, answer two ways: with π and another as a decimal. Don't forget units!
Check your answers with a table mate.
Page 5: Check answers
Practice #1
Page 5: Check answers
Practice #2
Remember: The measure of the central angle is equal to the measure of its intercepted arc.
What is arc length?
Which best describes arc length?
Arc Length equation:
Arc Length =
Arc Length Practice
On page 6, complete #3-5.
Leave in your answers and don't forget units!
Page 6: Check Answers
Practice #3
Page 6: Check Answers
Practice #4 Give 2 decimal places. Don't forget units!
Page 6: Check Answers
Practice #5 Leave in your answer. Don't forget units!
Converting Measurement Types
There are two ways to measure angles in a circle. We already know about degrees. The other method is called radians. To convert them, use this equation:
If you are given degrees, that will replace "deg". If you are given a number with , it will replace "rad".
Radian answers usually contain and are fractions.
Page 6: Check Answers
Practice #1 (Degrees -> Radians)
Page 6: Check Answers
Practice #2 (Radians -> Degrees) Your answer should look like: # degrees
Work for #2. You can scroll/zoom.
Great work!
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