Angles in Circles

Angles in Circles

How to find Central and inscribed angles in circles

Central angle: angle=arc

Central angles have a vertex at the center of the circle. The arc created by the two radii is equal to the angle.

Draw

Draw a central angle.

Labelling

label the picture

Drag labels to their correct position on the image

intercepted arc

angle

vertex

center

Fill in the Blank

Complete the formula for central angles



angle

arc

Fill in the Blank

If a central angle is 80 degrees, then what is the measure of its intercepted arc?

Fill in the Blank

What is x?

Multiple Choice

Find x.

• x=5

• x=-5

• x=115

• x=120

Multiple Choice

Solve for the missing angle.

• 45^o
• 90^o
• 22.5^o
• 128^o

Multiple Choice

Find the measure of arc JH

• 93
• 130
• 120
• 95

Multiple Choice

• A
• B
• C
• D

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.

Draw

Draw an inscribed angle

Labelling

label the picture

Drag labels to their correct position on the image

center

intercepted arc

angle

vertex

Drag and Drop

complete the formula for an intercepted arc:

2(​ ​​​

Placeholder

)= ​ ​

Placeholder

or

​

Placeholder

= ​

Placeholder

Drag these tiles and drop them in the correct blank above

arc

angle

Fill in the Blank

What is x?

Multiple Choice

• A
• B
• C
• D

Multiple Choice

• A
• B
• C
• D

Multiple Choice

Solve for x.

• 10
• 85
• 170
• 180

Multiple Choice

Solve for x

• 3
• 4
• 5
• 6