Circles: I need a challenge! 1. Penny Pinscher is purchasing pepperoni pizzas for her pals. A pizza 10 inches in diameter costs $7.95, and a pizza 14 inches in diameter costs $15.45. Which is the better buy – purchasing two 10-­‐inch pizzas or one 14-­‐inch pizza? Explain your answer with calculations. 1
2. Find the area of the rectangle if the radius of each circle is 2 . Express your 3
answer as a simplified fraction. Tara Patel 6/17/14 2:13 PM
Comment [1]: 1 14 inch pizza Tara Patel 6/17/14 2:13 PM
Comment [2]: 392/3 1
The three touching circles shown are identical. Line segment AE is 5 units 3
long. How long is the curved path ABCDE? Express your answer as a simplified fraction in terms of π . 3. B
D
A
E
C
4. Tara Patel 6/17/14 2:13 PM
Comment [3]: 16 π /6 A ferris wheel has diameter 42 feet. How far will a rider travel during a 4-­‐
22
min ride if the wheel rotates once every 20 seconds? Use for π . 7
5. The tires of a racing bike are approximately 70 cm in diameter. a)
How far does a bike racer travel in 5 min if the wheels are turning at a 22
speed of 3 revolutions per second? Use for π . 7
Tara Patel 6/17/14 2:13 PM
Comment [4]: 1584 ft b)
How many revolutions does a wheel make in a 22 km race? Use 22
for π 7
6. In the diagram, the length of a diameter of the circle is 2 and the length of a side of the square is 3. Find the area of space inside the square but outside the circle. Express your answer in terms of π . 7. Find the complete perimeter the figure below. Express your answer in terms of π with whole numbers. Tara Patel 6/17/14 2:13 PM
Comment [5]: a)198,000 cm (or 1.98 km) b)10,000 Tara Patel 6/17/14 2:13 PM
Comment [6]: 9-­‐pi Tara Patel 6/17/14 2:13 PM
Comment [7]: 6+7 π 3
4
3
8. Awful Kanaufil plans to ride his bike on a single-­‐loop track. There is 100 m of straight track before the loop and 20 m after. The loop has a radius of 15 m. To the nearest meter, what is the total length of the track he must ride? 9. There are 100 turns of thread on a spool with a diameter of 4 cm. Find the length of the thread to the nearest cm. Tara Patel 6/17/14 2:13 PM
Comment [8]: ~ 214 m Tara Patel 6/17/14 2:21 PM
Comment [9]: ~1257 cm