Monday, November 4th

WARM UP

Fill in the blank1. A chord is a segment whose

__________are on the circle2. A secant line intersects the

circle__________.

Vocab Review

D =

r = ?

r = D =

Find the diameter or

radius for each circle

Use P to determine whether each statement is true or false.

P

Q

R

TS

diameter. a is .1 RTFalse

radius. a is .2 PSTrue

chord. a is .3 QT

True

Secant Line:intersects the circle at exactly TWO points

a LINE that intersects the circle exactly

ONE time

Tangent Line:

Forms a ______angle

Name the term that best describes the notation.

Secant

Radius

DiameterChord

Tangent

CentralAngles

Angle measure of a line

A line measures 180˚Supplementary angles = 180˚

P

20˚x˚

Find x

Angle measure of a line

P

20˚x˚

Find x

30˚

Angle measure of a line

P

4x+2˚x˚

Find x

P

A

BC

Central Angle : An Angle whose vertex is at the center of the

circleMinor ArcMajor Arc

Less than 180°

More than 180°

ABACB

To name: use 2 letters

To name: use 3 letters

<APB is a Central Angle

P

E

F

D

Semicircle: An Arc that equals 180°

EDF

To name: use 3 letters

measure of an arc = measure of central angle

A

B

C

Q 96

m AB

m ACB

m AE

E

=

=

=

96°

264°

84°

Arc Addition PostulateA

B

C

m ABC =

m AB + m BC

Tell me the measure of the following arcs.

80100

40

140A

B

C

D

R

m DAB =

m BCA =

240

260

Congruent Arcs have the same measure and MUST come from the same circle or of congruent circles.

4545

A

BC

D

110

Arc length is proportional to “r”