Circle Vocabulary and Central Angles

​Name a Circle

​Use the middle letter. Example: Circle O.

What is a Line?

• a line goes on and on in both directions

• we show this by putting "arrowheads" on each end

What is a Segment?

• a segment is part of a line

• we show a line segment by putting dots on each end

• the dots show that the line has a starting point and a stopping point

What is a Ray?

• it begins at one point and continues on in one direction without end

• we show this by adding an arrowhead on one end and a dot on the other

What is a point?

• A point in geometry is a location. It has no size (no width, no length, and no depth)

• A point is shown by a dot

Multiple Choice

Which of these is a segment?

Multiple Choice

Which of these is a ray?

Multiple Choice

Which of these is a line?

Multiple Choice

Which of these is a point?

Multiple Choice

Identify this picture.

• ray AB

• line AB

• line segment AB

• point AB

Multiple Choice

Name the figure

• Line WX
• Segment WX
• Ray WX
• Ray XW

Multiple Choice

Name the figure

• Line ST
• Line TS
• Ray ST
• Ray TS

This LINE SEGMENT has a name

We call it "line segment AB" or "line segment BA" a short way of writing it is circled below the line segment

How is this different than a line segment?

This is called a LINE

This LINE has a name

We call it "line AB" or "line BA". A short way of writing it is circled below the line segment

Imagine a line segment that goes on without end IN ONLY ONE DIRECTION

This is called a RAY

This RAY has a name... Ray CD

When we write the name of a RAY the ENDPOINT (here it is C) is ALWAYS WRITTEN FIRST

Multiple Choice

What is ONE of the parallel line segments on this shape?

Multiple Choice

Name the Circle

• Circle C

• Circle A

• Circle E

• Circle B

Multiple Choice

Name a Chord

• $$\overline{CP}$$  

• $$\overleftarrow{A}\overrightarrow{B}$$  

• $$\overline{BA}$$  

• $$\overleftarrow{D}\overrightarrow{P}$$  

Multiple Choice

Name a Tangent

• $$\overline{BA}$$  

• $$\overleftarrow{A}\overrightarrow{B}$$  

• $$\overline{CP}$$  

• $$\overleftarrow{D}\overrightarrow{P}$$  

Multiple Choice

Name a Point of Tangency

• $$Point\ C$$  

• $$\overleftarrow{A}\overrightarrow{B}$$  

• $$Point\ P$$  

• $$\overleftarrow{D}\overrightarrow{P}$$  

Multiple Choice

Name a Secant

• $$\overline{PQ}$$  

• $$\overleftarrow{P}\overrightarrow{Q}$$  

• $$\overline{MK}$$  

• $$\overleftarrow{M}\overrightarrow{K}$$  

Multiple Choice

A line that touches one point on the circle.

• Tangent

• Secant

• Chord

• Arc

Multiple Choice

A line that touches two points on the circle.

• Chord

• Secant

• Tangent

• Arc

Multiple Choice

A line segment that touches two points on the circle.

• Tangent

• Secant

• Arc

• Chord

Multiple Choice

How many degrees does a circle have?

• less than 180

• equal to 180

• more than 180

• 360

Central Angle

• A central angle of a circle has a vertex at the center and is formed by two radii.

• The measure of the central angle is the same as the measure of its corresponding arc of the circle.

Fill in the Blanks

Multiple Choice

Find the measure of  $$\angle AOB$$   

• $$m\angle AOB=27\degree$$  

• $$m\angle AOB=333\degree$$  

• $$m\angle AOB=207\degree$$  

• $$m\angle AOB=13.5\degree$$  

Inscribed Angle: angle=1/2*arc or arc=2*angle

Inscribed angles must have a vertex touching the circle. The angle is half of the outside arc or the arc is twice the angle inside.

Fill in the Blanks

Multiple Choice

• $$m\angle PQR=68\degree$$

• $$m\angle PQR=34\degree$$

• $$m\angle PQR=292\degree$$

• $$m\angle PQR=112\degree$$

Fill in the Blanks

Intro to Arc in a cirlce

Hey guys remember a circle 360 degrees and a portion of a circle is called an Arc, which looks like a slice of pizza. There are three types of Arcs called Minor, Major, and Semicircle.

Multiple Choice

How many degrees does a minor arc have?

• less than 180

• equal to 180

• more than 180

• 360

Multiple Choice

How many degrees does a major arc have?

• less than 180

• equal to 180

• more than 180

• 360

Multiple Choice

Name a Major Arc

Multiple Choice

Name a Minor Arc

Multiple Choice

An arc that goes around the circle exactly 180 degrees

• Major Arc

• Minor Arc

• Semicircle

• Arc

Multiple Choice

An arc that goes around the circle less than 180 degrees

• Minor Arc

• Major Arc

• Arc

• Semicircle

Multiple Choice

An arc that goes around the circle more than 180 degrees

• Major Arc

• Minor Arc

• Semicircle

• Arc

Multiple Choice

What is the name of this circle?

• K

• IJ

• JKI

• KI

Multiple Choice

Which segment is a chord?

• $$\overline{AF}$$

• $$\overline{BH}$$

• $$\overline{CD}$$

Multiple Choice

What is  $$\overleftarrow{B}\overrightarrow{D}$$  ?

• a chord

• a secant line

• a tangent line

Multiple Choice

Which line segment is the diameter?

• $$\overline{DE}$$

• $$\overline{BA}$$

• $$\overline{BC}$$

• $$\overline{DC}$$

Multiple Choice

A line that touches a circle in just one point.

• tangent
• chord
• secant
• radius

Multiple Choice

Which of the following represents a secant?

• segment GD

• line XM

• segment AC

• line AC

Multiple Choice

Which of the following represents a tangent?

• line XM

• point X

• segment AC

• line AC

Multiple Choice

Which of the following represents a chord?

• segment XM

• segment GD

• segment GJ

• line AC

Multiple Choice

What does segment GD represent?

• radius

• diameter

• tangent

• secant

Multiple Choice

What is the name of the circle?

• circle geometry

• circle GJD

• circle X

• circle J

Multiple Select

Which of the following represents a minor arc? *Check all that apply*

• arc ACE

• arc BC

• arc BDE

• arc EA

Multiple Select

Which of the following represents a major arc? *Check all that apply*

• arc ACE

• arc ABC

• arc BCE

• arc EA

Multiple Choice

What type of angle is shown below?

• tangent angle

• inverse angle

• central angle

• circle angle

Multiple Choice

Which of the following represents the point of tangency?

• point J

• point X

• point M

• point C

Multiple Choice

This is a picture of ___________.

• Minor Arc
• Major Arc
• Semi-Circle
• Central Angle

Multiple Choice

This is a picture of ___________.

• Minor Arc
• Major Arc
• Semi-Circle
• Central Angle

Multiple Choice

This is a picture of ___________.

• Minor Arc
• Major Arc
• Semi-Circle
• Central Angle

Multiple Choice

This is a picture of ___________.

• Chord
• Diameter
• Radius
• Inscribed Angle

Multiple Choice

• center
• diameter
• radius

Multiple Choice

What is AF?

• Chord

• Radius

• Secant

• Tangent

Multiple Choice

Find the red minor arc and its measure.

• MN, 170

• MN 190