Think you’ve got your head wrapped around **Circles**? Put your knowledge to
the test. Good luck — the Stickman is counting on you!

Q. A circle divides a plane into ___ regions, including the circle itself.

1

2

3

4

5

Q. In the following figure, points *A*, *B*, and *C* are on ⊙*O*. Which of the following angles are central angles of ⊙*O*?

∠*AOC* only

∠*OBC* only

∠*OBC* and ∠*OCB* only

∠*AOC*, ∠*AOB*, and ∠*BOC* only

All angles in the figure are central angles

Q. The radius of ⊙*P* is 3 cm. What is the exact circumference of ⊙*P*?

3π cm

6π cm

9π cm

1.5π cm

cm

Q. Suppose arc *AB* and arc *CD* are congruent. Which of the following is a true statement?

Arc *AB* and arc *CD* have the same measure, but they might not have the same length.

Arc *AB* and arc *CD* have the same length, but they might not have the same measure.

Arc *AB* and arc *CD* have the same length and the same measure, but they might not have the same radius.

Arc *AB* and arc *CD* have the same length, the same measure, and the same radius.

None of the above

Q. Arc *ST* has measure 60° and radius 6 cm. What is the exact length of arc *ST*?

2π cm

36π cm

2π°

36π°

360°

Q. In the figure below, points *A*, *B*, and *C* are on ⊙*O*. If m∠*AOB* = 30° and ∠*BOC* is a right angle, what is the measure of arc *ABC*?

30°

90°

60°

120°

240°

Q. In the figure below, points *A*, *B*, *C*, and *D* are points on ⊙*O* and lines *AC* and *BD* intersect at *O*. m∠*AOB* = 24°. Distance *OB* is 5 km. What is the exact measure of arc *BC*?

24°

156°

204°

km

km

Q. Suppose arc *LM* and arc *PQ* have the same length. Which of the following must be true?

Arc *LM* and arc *PQ* have the same measure.

Arc *LM* and arc *PQ* have the same radius.

Arc *LM* and arc *PQ* are congruent.

Arc *LM* and arc *PQ* are the same arc.

None of the above

Q. The circumference of ⊙*O* is exactly 56 m. Which of the following is closest to the radius of ⊙*O*?

17 m

4 m

178 m

18 m

9 m

Q. A semicircle always _____.

is a major arc

is a minor arc

is an arc with measure 180°

subtends a central angle that is acute

has an arc length equal to its arc measure