Naming Angles

Labeling Angles and Arcs

Labeling Angles

Ways to label angles

• By the Vertex: $\angle O$   

• By the points:  $\angle AOB$        (Vertex should always be in the middle of two points)

• If angles are numbers then can be labeled by number.           Example:  $\angle1$  

Multiple Select

Choose the correct way(s) to label the angle.

• $$\angle ABC$$

• $$\angle CBA$$

• $$\angle B$$

• $$\angle C$$

Labeling Arcs

Ways of Labeling Arcs

• Use the endpoints of the arc:

• CB or BC would be the blue arc

• CDB or BDC would be the red arc (use points in-between endpoints to indicate which direction to go in)

• Arc CBD (Start at C, go to B then go to D)

Multiple Select

Choose the correct way to label the pink arc

• CB

• CAB

• AB

• BAC

• CDB

Multiple Select

Check the boxes that have the correct label for the red arc.

• CDB

• CB

• D

• CAB

• BDC

Labeling Angles in Circles, and Intercepted arcs

Labeling arcs and angles

• Labeling angles stays the same as before

• Labeling the arc stays the same

• The intercepted arc corresponds to the endpoints of the angle. Example: The intercepted arc of  $\angle EDG$  is Arc GE

Labeling Inscribed Angles and Arcs

Labeling Inscribed Angles is the same as normal angles
Labeling Arcs is the same.
Example: the inscribed angle is  $\angle EFG$  and the intercepted arc would be the endpoints of the angle EG

Multiple Select

Correctly choose the correct names for the central angle and its intercepted arc

• $$\angle CDA$$ ; Arc BD

• $$\angle FEB$$ ; Arc BCF

• $$\angle CAD$$ ; Arc CFD

• $$\angle CFE$$ ; Arc BED

Multiple Select

Correctly choose the correct names for the inscribed angle and its intercepted arc

• $$\angle CDA$$ ; Arc BD

• $$\angle FEB$$ ; Arc BFD

• $$\angle CAD$$ ; Arc CFD

• $$\angle CFE$$ ; Arc BED