Circles, Arcs & Sectors Quiz

1. A circle has radius 7 cm. What is its circumference, in terms of $\pi$?

• A. $7\pi$ cm
• B. $14\pi$ cm
• C. $49\pi$ cm
• D. $21\pi$ cm

2. A circle has diameter 12 cm. What is its area, to 3 significant figures?

• A. $452 \text{cm}^2$
• B. $113 \text{cm}^2$
• C. $37.7 \text{cm}^2$
• D. $144 \text{cm}^2$

3. A sector has radius 9 cm and angle 40°. What is its arc length, to 3 significant figures?

• A. $3.14$ cm
• B. $6.28$ cm
• C. $12.6$ cm
• D. $4.71$ cm

4. A sector has radius 10 cm and angle 72°. What is its area, to 1 decimal place?

• A. $62.8 \text{cm}^2$
• B. $78.5 \text{cm}^2$
• C. $50.3 \text{cm}^2$
• D. $31.4 \text{cm}^2$

5. A sector has radius 5 cm and angle 144°. What is its perimeter, to 3 significant figures?

• A. $12.6$ cm
• B. $10.0$ cm
• C. $22.6$ cm
• D. $15.7$ cm