Unit 6: Circles

Basics

100

What is straight line from the center of a circle to a point on the circumference?

radius

200

What is the distance around the edge of a circle called?

circumference

300

What is a straight line through the center of a circle to two points on the circumference?

diameter

400

What is a portion of the circumference of a circle?

arc

500

What is a shape enclosed by two radii and the arc between them?

sector

Arc Length 1

100

If a circle has a radius of 6, what is the arc length formed by a central angle of 60 degrees?

Leave in terms of pi

2 pi

200

If a circle has a radius of 9, what is the arc length formed by a central angle of 120 degrees?

Leave in terms of pi

6 pi

300

If a circle has a radius of 8, what is the arc length formed by a central angle of 270 degrees?

Leave in terms of pi

12 pi

400

If a circle has a radius of 7, what is the arc length formed by a central angle of 125 degrees?

Leave in terms of pi

4.9 pi or 175/36 pi

500

If a circle has a diameter of 20, what is the arc length formed by a central angle of 300 degrees?

Leave in terms of pi

16.7 pi or 50/3 pi

Sector Area 1

100

If a circle has a radius of 12, what is the sector area formed by a central angle of 120 degrees?

Leave in terms of pi

48 pi

200

If a circle has a radius of 10, what is the sector area formed by a central angle of 45 degrees?

Leave in terms of pi

12.5 pi or 25/2 pi

300

If a circle has a radius of 8, what is the sector area formed by a central angle of 225 degrees?

Leave in terms of pi

40 pi

400

If a circle has a radius of 15, what is the sector area formed by a central angle of 311 degrees?

Leave in terms of pi

194.4 pi or 1555/8 pi

500

If a circle has a diameter of 10, what is the sector area formed by a central angle of 143 degrees?

Leave in terms of pi

9.9 pi or 715/72 pi

Arc Length 2

100

If a circle has a radius of 4, what is the arc length formed by a central angle of 90 degrees?

Leave in terms of pi

2 pi

200

If a circle has a radius of 5, what is the arc length formed by a central angle of 90 degrees?

Leave in terms of pi

2.5 pi or 5/2 pi

300

If a circle has a radius of 10, what is the arc length formed by a central angle of 45 degrees?

Leave in terms of pi

2.5 pi or 5/2 pi

400

If a circle has a radius of 6, what is the arc length formed by a central angle of 70 degrees?

Leave in terms of pi

2.3 pi or 7/3 pi

500

If a circle has a diameter of 4, what is the arc length formed by a central angle of 90 degrees?

Leave in terms of pi

1 pi

Sector Area 2

100

If a circle has a radius of 5, what is the sector area formed by a central angle of 90 degrees?

Leave in terms of pi

6.25 pi or 25/4 pi

200

If a circle has a radius of 9, what is the sector area formed by a central angle of 90 degrees?

Leave in terms of pi

20.25 pi or 81/4 pi

300

If a bike tire has a radius of 15, what is the sector area formed by a central angle of 100 degrees?

Leave in terms of pi

62.5 pi or 125/2 pi

400

If a cookie has a radius of 4, what is the sector area formed by a central angle of 180 degrees?

Leave in terms of pi

8 pi

500

If a circle has a diameter of 8, what is the sector area formed by a central angle of 90 degrees?

Leave in terms of pi

4 pi