Over Lesson 10–1
Refer to the figure. Find BC.
3
A.
B.
C.
D.
A
B
C
D
Over Lesson 10–1
Refer to the figure. Find DE.
13
A.
B.
C.
D.
A
B
C
D
Over Lesson 10–1
Find the length of the radius of the circle.
6.5 in.
A.
B.
C.
D.
A
B
C
D
• Identify central angles, major arcs, minor
arcs, and semicircles, and find their
measures.
• Find arc lengths.
• central angle—an angle with a vertex in the
center of the cricle
• arc—a portion of a circle defined by two
endpoints on the circle. An arc has the same
measure of the central angle formed by its
endpoints.
Find Measures of Central Angles
Find the value of x.
Find Measures of Central Angles
The sum of the measures of
Substitution
Simplify.
Add 2 to each side.
Divide each side
by 26.
Answer: x = 7
Find the value of x.
9
A.
B.
C.
D.
A
B
C
D
Classify Arcs and Find Arc Measures
Answer:
Classify Arcs and Find Arc Measures
Classify Arcs and Find Arc Measures
Answer:
Classify Arcs and Find Arc Measures
Answer:
A.
B.
C.
D.
A
B
C
D
A.
B.
C.
D.
A
B
C
D
A.
B.
C.
D.
A
B
C
D
•congruent arcs—arcs in the same or
congruent circles that have the same
measure.
Find Arc Measures in Circle
Graphs
mLPK = 0.21(360)
= 75.6
Answer:
Find 21% of 360.
Simplify.
Find Arc Measures in Circle
Graphs
Find Arc Measures in Circle
Graphs
Sum of arc in circle is 360.
Substitution
Simplify.
Simplify.
Answer:
140.4
A.
B.
C.
D.
A
B
C
D
273.6
A.
B.
C.
D.
A
B
C
D
• adjacent arcs—arcs in a circle that have
exactly one endpoint in common.
Use Arc Addition to Find Measures of Arcs
.
Use Arc Addition to Find Measures of Arcs
Arc Addition Postulate
= mLH + mHI
= 58 + 32
= 90
Answer:
Substitution
Use Arc Addition to Find Measures of Arcs
Use Arc Addition to Find Measures of Arcs
Arc Addition Postulate
= mIJ + mJK
= 90 + 58
= 148
Answer:
Substitution
52
A.
B.
C.
D.
A
B
C
D
142
A.
B.
C.
D.
A
B
C
D
• arc length—the distance between the endpoints
along an arc measured in linear units. Since an
arc is a portion of a circle, its length is a fraction
of the circumference.
Find Arc Length
Arc Length Equation
Substitution
cm
Answer:
Use a calculator.
Find Arc Length
Arc Length Equation
Substitution
Use a calculator.
Answer:
Find Arc Length
Arc Length Equation
Substitution
Use a calculator.
Answer:
3.77 cm
A.
B.
C.
D.
A
B
C
D
38.61 cm
A.
B.
C.
D.
A
B
C
D
32.99 cm
A.
B.
C.
D.
A
B
C
D