Geometry
In-Class Notes
10.1 Parts of a Circle
Objective: I can identify segments and lines related to circles
Warm Up:
Draw/explain each of the following.
AB
EF
CD
GH
Name/complete each of the following.
F
E
B
D
5
H
G
C
I
_________ = 5
Definitions - Parts
Circle
Interior
N
Exterior
P
Radius
M
Diameter
Q
Congruent Circles
Chord
R
m
Secant
B
P
Tangent
F
Point of Tangency
A
E
Example
[a] Describe each of the following parts of
C.
B
J
AD
JK
K
A
C
F
EG
D
H
G
F
E
HB
CD
[b] Label the following circle with each of the following parts.

Radius CZ

Diameter XY

Tangent line VW at a point of tangency U

Secant line ST

Chord QR
C
[c] Label the following circle with each of the following parts.

Radius GO

Diameter CA

Tangent line RD at a point of tangency I

Secant line NA

Chord LS
G
[d] Describe what is wrong with each of the following statements.

Chord AB

Tangent Line YZ

Radius FG in circle

Secant line HI
C.
Definition
Picture
Tangent Circles
Concentric Circles
Review
Simplify each of the following radicals.
[a] 6 6  2 2
[b]
5 10 
2
[c]
6 5
2 10
Find the missing side lengths, then find the sine, cosine, and tangent of both A and B .
B
sin A 
sin B 
30°
C
A
cos A 
cos B
tan A 
tan B 
sin A 
sin B 
cos A 
cos B
tan A 
tan B 
6
A
10
B
C