Arc Measures

4.1a Central Angles and Arcs

SOL G.11.a

I can describe arc measures associated with central angles.

QUICK REVIEW

Remember this?

Central angles are angles with a vertex at the center of the circle.

Arcs are pieces of a circle's border.

The measure of a central angle is equal to the measure of its intercepted arc.

Central angles are like pie slices. Their intercepted arcs are the pie crust.

Multiple Choice

Name the arc intercepted by

$$\angle1$$  .

Multiple Choice

Which angle is intercepted by the arc HJ?

• $$\angle1$$

• $$\angle2$$

• $$\angle3$$

Multiple Choice

What is the measure of the missing arc?

• 160º

• 95º

• 80º

• 180º

Multiple Choice

What is the measure of the missing arc?

• 155º

• 145º

• 300º

• 180º

More Advanced

Find the measure of arc TS.

How might you find that arc TS?

Open Ended

How might you find the arc TS? Write down your thoughts. Try to be specific. What do you think the measure is?

Let's try this one.

Find the measure of the arc RS.

Open Ended

Do you have any questions about that last one?

Did you get the same answer?

Now you try... Find this practice assignment in your Module 4.

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