A circle has radius 10 units. For each angle measure, find the area of a sector of this circle with the given measure as its central angle.

1. radian
2. radians
3. 1 radian
4. 2 radians

Each circle has a shaded sector with a central angle measured in radians. What fraction of the circle is each sector?

Find the radian measure of each angle.

1. 30 degrees

2. 45 degrees

3. 50 degrees

Find the degree measure of each angle.

1. radians

2. radians

3. radians

4. 3 radians

Andre and Diego are each saving money. They each hope to save 500 dollars. They are tracking their progress on the circles in the images.

Diego thinks that Andre has saved more money than Diego has saved. Andre thinks they have saved the same amount. Do you agree with either of them? Explain or show your reasoning.

Clare missed class, and Jada is teaching her how to construct the circumscribed circle of a triangle. Here are the instructions Jada wrote.

“Construct all three perpendicular bisectors of the triangle’s sides. The point where the perpendicular bisectors intersect is called the ‘circumcenter.’ Construct a circle centered at the circumcenter with radius set to the distance between the circumcenter and a vertex. If the triangle has a circumscribed circle, the circle you construct will go through all three vertices.”

Do you agree with Jada’s instructions? Explain your reasoning.