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Created by W.L. Bass and used with permission, p.1
Honors Geometry – Chapter 6 Tentative Syllabus
YOU ARE EXPECTED TO CHECK YOUR ANSWERS BEFORE COMING TO CLASS.
Red
Day
Red
Date
Blue
Day
Blue
Date
Topic
Homework
(due next class period)
Fri
Nov 20
Mon
Nov 23
6.1 Tangent Properties
6.2 Chord Properties
In-class: 6.2 Wkbk p.40, #1–9
6.1 Wkbk: p.39, #1– 6
p.320, #1–13, 15–19
Tue
Nov 24
Mon
Nov 30
6.3 Arcs and Angles
6.4 Other Angles
In-class: 6.3 Wkbk… p.41
Circle Angle Chase #1 (Notes p.20)
p.327, #1–16, 22–24, 26
Circle Angle Chase #2 &
#3
(Notes p.21 and 22)
Tue
Dec 1
Wed
Dec 2
6.5 Circumference & Diameter
6.6 Around the World
In-Class: 6.5 Wkbk… p.43
p.337, #1–13
p.342, #2, 4, 6
Review for Final Exam #1 ( DUE on exam day)
Thurs
Dec 3
Fri
Dec 4
6.7 Arc Length
In-class: 6.7 Wkbk… p.45
p.351… 1–9, 17
Circle Angle Chase #4 (Notes p.23)
Mon
Dec 7
Tue
Dec 8
13.5 Indirect Proof Notes Review: Chp 6 Practice Test
p.359… 4–20, 25–28, 31, 32, 35, 38, 46, 47, 52, 53,
62, 63
Wed
Dec 9
Thurs
Dec 10
Chapter 6 Test
Indirect Proof Practice
Final Exam Review #2 (Due day of Final Exam)
Fri
Dec 11
Mon
Dec 14
Final Exam Review
Study for Final Exam
Tue
Dec 15
Wed
Dec 16
Enjoy Winter Break!
Created by W.L. Bass and used with permission, p.2
Section Indiana Standard Learning Target
6.1
6.2
GCl1 Define, identify, and use relationships
among the following: radius, diameter, arc,
measure of an arc, chord, secant, tangent, and congruent concentric circles.
GCl3 Identify and describe relationships among
inscribed angles, radii, and chords, including the following: the relationship exists between
central, inscribed, and circumscribed angles; inscribed angles on a diameter are right angles;
and the radius of a circle is perpendicular to a
tangent where the radius intersects the circle. GCl6 Construct a tangent line to a circle through
a point on the circle, and construct a tangent line
from a point outside a given circle to the circle;
justify the process used for each construction.
Review and use basic properties of a circle
and circle vocabulary.
Discover and use properties of tangents of circles.
Construct a tangent line (Investigation 2)
Discover and use properties of chords in a circle.
(p.322 #23)
6.3 GCl1 Define, identify, and use relationships among the following: radius, diameter, arc,
measure of an arc, chord, secant, tangent, and
congruent concentric circles. GCl4 Solve real-world and other mathematical
problems that involve finding measures of
circumference, areas of circles and sectors, and arc lengths and related angles (central, inscribed,
and intersections of secants and tangents).
Discover and use relationships between an inscribed angle of a circle and its
intercepted arc.
Construct a cyclic quadrilateral. Know and use that the opposite angles of a
cyclic quadrilateral are supplementary.
(Investigation 4)
6.4 GLP4 Develop geometric proofs, including direct
proofs, indirect proofs, proofs by contradiction and proofs involving coordinate geometry, using
two-column, paragraphs, and flow charts
formats.
Prove and use circle conjectures.
6.5 GCl1 Define, identify, and use relationships among the following: radius, diameter, arc,
measure of an arc, chord, secant, tangent, and
congruent concentric circles.
Calculate pi, the ratio of the circumference of a circle to its diameter.
6.6 GCl4 Solve real-world and other mathematical
problems that involve finding measures of circumference, areas of circles and sectors, and
arc lengths and related angles (central, inscribed,
and intersections of secants and tangents). GQP5 Deduce formulas relating lengths and
sides, perimeters, and areas of regular polygons.
Understand how limiting cases of such formulas lead to expressions for the circumference and the
area of a circle.
Apply circle properties and the
circumference of a circle to solve problems. (p.343 #9)
6.7 GCl4, GCl5 Construct a circle that passes
through three given points not on a line and justify the process used.
Discover and use a formula for finding the
length of an arc of a circle. (p.354 #24)
Created by W.L. Bass and used with permission, p.3
BA
C
6.1 and 6.2 Notes
Tangent and Chord Properties
Big ideas about TANGENTS!
1. A tangent and a radius are perpendicular
to each other at the point of tangency.
Label the picture based on the property.
2. Tangent segments from the same point
outside a circle are congruent.
Label the picture based on the property.
3. Recall: The measure of an arc is equal
to the measure of its central angle.
If 115m ABC then
𝑚 𝐶�̂� = ______________
4. Recall: All the radii (plural of radius)
are congruent to each other in a circle.
Label the picture based on the property.
Apply the tangent theorems… Assume that lines that appear tangent are tangent.
1. 2. 3.
4. 5. 6.
x 255 x
33
x 65
x E 106
x 83 x
E
15
Created by W.L. Bass and used with permission, p.4
7. One more application
a.) Write an equation for the tangent line.
Find slope of the radius
Find slope of the tangent line (Hint: the radius and tangent are perpendicular)
Use the point-slope formula to write the equation for the tangent line.
1 1y y m x x
Rewrite the equation in slope-intercept form
b.) YOU TRY… Write an equation for the tangent line.
A little more vocabulary… Internally and Externally Tangent
Circles are considered internally or externally tangent when…
they are _________________ to the same _____________ at the same ______________.
Created by W.L. Bass and used with permission, p.5 H
D
G
FE
Big ideas about CHORDS
1. VOCABULARY – Central angle v. Inscribed Angle.
Central Angle – An angle that has its vertex on the ______________ of the circle
Inscribed Angle – An angle that has its vertex __________ the circle
AND the sides of the angle are __________________ of the circle.
Use the definitions above and the diagram at the below name the following…
Central Angles: __________________________________ Inscribed Angles: __________________________________
2. If two chords in a circle are congruent,
then their central angles are congruent.
Use your compass to show DE GH
Draw in radii FD , FE , FG , FH
DFE GFH by _____________
Therefore, DFE GFH
by _____________
3. If two chords in a circle are
congruent,
then their arcs are congruent.
From the “proof” above in Big Idea #2,
we saw that DFE GFH
Recall: The measure of an arc is ____________________ to the measure
of its central angle.
Therefore, if the central angles are
congruent, then 𝐷𝐸̅̅ ̅̅ ≅ 𝐺𝐻̅̅ ̅̅
Label the picture
based on the Big Ideas 2 & 3.
H
O
U
N
D
C
O
R
K
M
A
T
H
Created by W.L. Bass and used with permission, p.6
H
D
G
FE
N
O
PQ
4. The perpendicular from the center of a
circle to a chord bisects the chord.
Construct a perpendicular from F
to DE and label the intersection M.
Use your compass to show DM ME
Construct a perpendicular from F
to GH and label the intersection P
Use your compass to show GP PH
5. If two chords in a circle are congruent,
then they are equidistant from the
center.
Recall: Distance from a point to
line/segment must be measured on a _______ line.
Since we’ve already constructed the
perpendicular in Big Idea #4…
Use your compass to show FM FP .
Label the picture
based on Big Ideas 4 & 5.
6. The perpendicular bisector of a chord is also the diameter of the circle.
Construct the perpendicular bisector of NO … Name the bisector m.
Construct the perpendicular bisector of PQ … Name the bisector p.
Label the intersection of m and p point F.
Summary:
Both ______ and ______ contain diameters of the circle.
Point ______ is the _____________of the circle!
Created by W.L. Bass and used with permission, p.7
I
N
OP
6.3 Notes
Arcs and Angles
Review/Warm-up… Write the equation for the tangent line shown below.
6.3 BIG IDEAS!
1. VOCABULARY – Central angle v. Inscribed Angle.
Central Angle – An angle that has its vertex on the ______________ of the circle
Inscribed Angle – An angle that has its vertex __________ the circle
AND the sides of the angle are __________________ of the circle.
2. The measure of an inscribed angle is one-half the measure of its intercepted arc.
Use a piece of patty paper to trace 2 m N
Draw central angle OIP
Compare 2 m N to m I
Recall: The measure of an arc is ____________________ to the measure of its central angle.
Summary:
_____________ _____________m I
1
______________2
m I
2 ______________m N
Measure of Inscribed Angle = ___________________
Measure of Intercepted Arc = ___________________
Created by W.L. Bass and used with permission, p.8
I
N
OP
R
U
TS
W
Y Z
W
X
3. Inscribed angles that intercept the
same arc (or congruent arcs) are congruent.
The intercepted arc for O is _________
The intercepted arc for P is _________
Use a piece of patty paper to show O P
What about N and R ?
4. Parallel lines (segments) intercept
congruent arcs.
If / /ST WU , then 𝑆�̂� ≅ _____________
Why? Draw transversal SU .
TSU WUS because…
______________________________
Look again at Big Idea #3...
Congruent Arcs Congruent angles
5. Angles inscribed in a semicircle are right angles.
Draw inscribed YWZ
What’s the measure of its intercepted arc?_________
Therefore __________m W
Draw inscribed ZXY
What’s the measure of its intercepted arc?_________
Therefore __________m Z
What kind of triangles are
YWZ and ZXY ? _________________________.
Are they congruent to each other? _____________.
Are they isosceles? _____________.
Created by W.L. Bass and used with permission, p.9
I
N
O
P
R
6. The opposite angles in a cyclic quadrilateral are supplementary.
Definition: Cyclic quadrilateral
____________________________________________
Examine m N m R … What do you
notice?__________________________
Therefore…
N and ______________ are supplementary
Use a piece of patty paper to trace m O m P …
What do you notice?__________________________
Therefore…
O and ______________ are supplementary
Apply what you have learned… Solve for the variable in each diagram.
1. 2. 3. 4.
5. 6. 7. 8.
9. 10. Hint: Write the formula first. 11.
x˚
y˚
x˚
105˚
(2x + 11)˚
(4x - 3)˚
A
B
C
D
48˚ C
B
A
x˚ B
A
C
87˚ x˚ C A
B
28˚
x˚
37˚
B
A
C x˚
208˚
(5x + 4)˚
142˚
C B
A D
x˚
A
B
C
138˚
x˚
x˚
y˚
110˚
Created by W.L. Bass and used with permission, p.10
Ch 6 Exploration
Other Angle Measures
Match the conjecture to the appropriate diagram below then write an equation to find in marked angle.
1.___________ Intersecting Secants Conjecture: The measure of an angle formed by 2 secants that intersect
________ the circle is ___________________
2.___________ Intersecting Chords Conjecture: The measure of angle formed by 2 intersecting
______________ (or 2 secants intersecting inside) is ___________________
3.___________ Tangent-Secant Conjecture: The measure of an angle formed by an intersecting tangent and a
secant to a circle is ___________________
4.___________ Intersecting Tangents Conjecture: The measure of angle formed by 2 intersecting
______________ to a circle is ___________________
5.___________ Tangent Chord Conjecture: The measure of an angle formed by the intersection of a tangent
and a chord at the point of tangency is ___________________
A. B. C.
D. E.
T
B
E
1
A
T
B
E
1 A
T
S
B
E
1
A
A
B
C
D
1
Z
P
A
E
1
Created by W.L. Bass and used with permission, p.11
Apply what you know…
1. Finding Angle and Arc Measures
a.) Given: 𝑚𝐵�̂� = 54°, mark this in the picture.
b.) 𝑚 𝐶𝐸�̂�= ____________
c.) Find the intercepted arc for ABC and m ABC = ____________
d.) Find the intercepted arc for CBD and m CBD = ____________
e.) What do you notice about ABC and CBD ?
2. Finding the Measure of an Angle Formed by Two Chords
a.) Solve for x .
b.) Solve for x .
A B
D
C
E
E is not the center!
A
B
E
C
D
24 100 x
E is not the center!
center!
A
B
E
C
D
30 75 x
Created by W.L. Bass and used with permission, p.12
3. Finding angles and arcs when intersection is OUTSIDE the circle.
a..) Solve for x .
Mark the intercepted arcs
b.) Solve for x .
Mark the intercepted arcs
c.) Solve for x .
Mark the intercepted arcs
𝑚𝐴�̂�= ____________,
d.) Solve for x .
Mark the intercepted arcs
𝑚𝐶�̂� = ____________,
e.) Solve for x .
Mark the intercepted arcs
𝑚𝐴𝐶�̂�= ____________,
f.) Solve for x .
Mark the intercepted arcs
𝑚𝐴𝐶�̂�= ____________,
6.5 and 6.6 Notes
A
B
C
D
110 x 49
x C
B
E A
56
x 125
A
B
C
x 52
A
B
C
A
B
C
D
114 x 50
x
C
B
E A
36
Created by W.L. Bass and used with permission, p.13
Circumference/Diameter, Around the
World
6.5 – Circumference Conjecture
If C is the circumference and d is the diameter of a circle, then there is a number such that
_________C .
If r is the radius then _________d and _________C
1. If 7C m , find the radius.
2. If 8.5d m , find the circumference
(no decimals).
3. If 36C m , find the radius.
4. If 6.25d m , find the circumference
(no decimals)
6.6 Practice…
5. A satellite in a nearly circular orbit is 2000 km above the Earth’s surface. The radius of the Earth is approximately 6400 km. If the satellite completes its orbit in 12 hours, calculate the speed of the
satellite in km per hour.
6. The diameter of a car tire is approximately 60 cm (0.6 m). The warranty is good for 70,000 km. about
how many revolutions will the tire make before the warranty is up? More than a million? More than a billion? (1 km = 1000m)
7. Goldi’s Pizza Palace is known throughout the city. The small Baby Bear pizza has a 6-inch radius and
sells for $9.75. The savory medium Mama Bear pizza sells for $12.00 and has an 8 inch radius. The
large Papa Bear pizza is a hefty 20 inches in diameter and sells for $16.50. The edge is stuffed with cheese and it’s the best part of the pizza. What size has the most pizza edge per dollar? What is the
circumference of this pizza?
6.7 Notes
Arc Length
Created by W.L. Bass and used with permission, p.14
U
G
H50
9
6.7 – Finding Arc Length v. Arc Measure
The ___________________ of an arc is equal to…
Definition…
Proportion…
Find the indicated measures.
1.
𝑚𝐺�̂� = _________ 𝑚𝐻𝑈�̂� = __________ length of 𝐻𝑈�̂�=___________
Created by W.L. Bass and used with permission, p.15
R
A
T
70
P
1160
Y
U
P
2.
𝑚𝑌�̂� = ___________ 𝑚𝑌𝑈�̂� = __________ length of 𝑌�̂� =______________
3. WORKING BACKWARDS…
Given: 𝐴�̂� = 16𝜋
𝑚𝐴�̂� =___________𝑚𝐴𝑅�̂�=_____________Diameter = ___________
Created by W.L. Bass and used with permission, p.16
13.5 Notes
Indirect Proof
General steps for an indirect proof…
A.
B.
1. Given: 1 is not to 2
Prove: p is not // n
Statement Reason
a.) ____________________________ a.) ____________________________
b.) ____________________________ b.) ____________________________
c.) ____________________________ c.) ____________________________
d.) ____________________________ d.) ____________________________
2. Given: 1 67m
Prove: BX is not to AC
Statement Reason
a.) ____________________________ a.) ____________________________
b.) ____________________________ b.) ____________________________
c.) ____________________________ c.) ____________________________
d.) ____________________________ d.) ____________________________
e.) ____________________________ e.) ____________________________
2 1
p
n
1
X
B
A C
Created by W.L. Bass and used with permission, p.17
3. Given: 1 is not to 2
Prove: ABC is not isosceles with vertex angle B
Statement Reason
a.) ____________________________ a.) ____________________________
b.) ____________________________ b.) ____________________________
c.) ____________________________ c.) ____________________________
d.) ____________________________ d.) ____________________________
4. Given: OJ OK
JE is not to KE
Prove: OE does not bisect JOK
Statement Reason
a.) ____________________________ a.) ____________________________
b.) ____________________________ b.) ____________________________
c.) ____________________________ c.) ____________________________
d.) ____________________________ d.) ____________________________
e.) __________OJE e.) ____________________________
f.) ____________________________ f.) ____________________________
g.) ____________________________ g.) ____________________________
h.) ____________________________ h.) ____________________________
E
J
1 2
O
K
1 A
2 C
B
Created by W.L. Bass and used with permission, p.18
31
96E
BC
D
A
Circle Angle Chase #1
Given: EC is a diameter
For each problem, determine the measure of the arc or angle. Be careful to look where your vertex is.
One mistake can lead to many! Write your answers on the blanks.
Write your answers on the blanks provided.
1. m EBA _________
2. mEA _________
3. mAC _________
4. mED _________
5. mDC _________
6. m E _________
7. m D _________
8. m ECA _________
9. m A _______
Created by W.L. Bass and used with permission, p.19
# 11
# 5
# 12# 10
# 7
# 6
# 9
# 8
# 4
# 3
# 13
# 14
# 2
# 1
70
85
Circle Angle Chase #2
Given: AB is a diameter
For each problem, determine the measure of the arc or angle. Be careful to look where your vertex is.
One mistake can lead to many!
Write your answers on the blanks provided.
1. _________
2. _________
3. _________
4. _________
5. _________
6. _________
7. _________
8. _________
9. _________
10. _________
11. _________
12. _________
13. _________
14. _________
A
B
Created by W.L. Bass and used with permission, p.20
# 6
# 5
# 13 # 14
# 12# 15
# 10# 11
# 9
# 7
# 1
# 8
# 2
# 4
# 3
37
40
E
A
C
D
Circle Angle Chase #3
Given: //AC DE
For each problem, determine the measure of the arc or angle. Be careful to look where your vertex is.
One mistake can lead to many!
Write your answers on the blanks provided.
1. _________
2. _________
3. _________
4. _________
5. _________
6. _________
7. _________
8. _________
9. _________
10. _________
11. _________
12. _________
13. _________
14. _________
15. _________
Created by W.L. Bass and used with permission, p.21
Circle Angle Chase #4
For each problem, determine the measure of the arc or angle. Be careful to look where your vertex is.
One mistake can lead to many!
Write your answers on the blanks provided.
1. _________
2. _________
3. _________
4. _________
5. _________
6. _________
7. _________
8. _________
9. _________
10. _________
11. _________
12. _________
13. _________
14. _________
42˚
44˚
18˚
#1
#2
#3
#4
#5
#7
#6
#9
#10
#8
#11
#12
#13
#14
Created by W.L. Bass and used with permission, p.22
CHAPTER 6 CIRCLE SUMMARY
1.
4.
7.
10.
2.
5.
8.
11.
3.
6.
9.
Other things to remember…
Congruent chords
_____________________
Congruent arcs
_____________________
How to find the center of
a circle with only 3 points
How to write the
equation of a tangent line.
Circumference Formula
Arc Length