Geometry B
Name:______________________
Date: ___________
Chapter 11: Circles
Section 11.2: Arcs & Chords
DO NOW
1) What percent of 60 is 18?
2) What number is 44% of 6?
3) Find mWVX.
Objectives of Lesson: TSW apply properties of arcs. TSW apply properties
of chords.
Why learn this? Market analysts use circle graphs to
compare sales of different products.
A central angle______________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
ARC
A minor arc is an arc
whose points are on
or in the interior of a
central angle.
A major arc is an arc
whose points are on
or in the exterior of
a central angle.
If the endpoints of an
arc lie on a diameter,
the arc is a semicircle .
MEASURE
DIAGRAM
2
Writing Math: _____________________________________________
_________________________________________________________
Example 1: Data Application
The circle graph shows the types of grass planted in the yards of one
neighborhood. Find mKLF.
Example 2: Use the graph to find each of the following.
a. mFMC
b. mAHB
c. mEMD
Adjacent arcs______________________________________________
_________________________________________________________
_________________________________________________________
Arc Addition Postulate
3
Example 3: Using the Arc Addition Postulate
Find mBD.
Example 4: Using the Arc Addition Postulate
Find mJKL
Example 5
Find mLJN
Within____________________________________________________
_________________________________________________________
4
Theorem
Hypothesis
In a circle or congruent circles,
Example 6: Applying Congruent Angles, Arcs, and Chords
TV  WS. Find mWS.
Example 7: Applying Congruent Angles, Arcs, and Chords
C  J, and mGCD  mNJM. Find NM.
Conclusion
5
Example 8: PT bisects RPS. Find RT.
Example 9: Find each measure. A  B, and CD  EF. Find mCD.
Theorem
Hypothesis
In a circle,
In a circle,
Example 10: Using Radii and Chords: Find NP.
Conclusion
6
Example 11
Find QR to the nearest tenth.
Example 12: If a picnic area is located at the midpoint
between Sacramento and Oakland, find the distance
to the picnic area from the road sign.
Example 13: E is the midpoint of DF, DE = 2x + 4, and EF = 3x - 1. Find DE,
EF, and DF.
Example 14: Q bisects PR , PQ = 3y, and PR = 42. Find y and QR.
smilardo.wordpress.com - homework: worksheets: link to book and more
http://www.facebook.com/groups/Milardo.Math/