Name ___________________________________________Date ____________Hr ______HW#____

Unit 3 Review~ Circumference and Area 1. Here is a circle with center and some line segments and curves joining points on the circle.

True or False?AB is a radius ___________OC is a radius ___________PQ is a diameter ___________BA is a diameter ___________If BA=6, then OC= 3 ___________If OA=4, then PQ= 8 ___________BA= PQ ___________OB= AO ___________OC= PQ ___________

2. Matthew measured some circles and recorded his measurements. Which measurements are acceptable, and which are inaccurate. Show a reason why for each.

diameter Circumference Do these measurements make sense?

Why or why not?

5.2 cm 1.7 cm

14 cm 56 cm

19.1 cm 59.2 cm

6.2 cm 19.5 cm

16 cm 33.6 cm

3. Complete the table. Use 3.14 for π. Label each answer.radius diameter Circumference8.9 ft3.2 cm

25 in10.6 cm

49 cm32.6 m

4.

If AE = 12 m, find: AG ______________ CD _______________ circumference of circle A _________________

If FE = 10, findAG ______________ CD _______________ circumference of circle A _________________

5. Identify each measurement as the diameter, radius, or circumference of the circular object. Then, find the other two measurements for the circle. Be sure to indicate which is which measurement.

The crust on a pizza is 37.7 inches. This represents _____________________.

You swim straight across a circular pool for 30 ft. This represents ___________________.

The blade on a fan is 18 inches. This represents ______________________.

6. Find the distance around this figure.

7. The diameter of a bike wheel is 30 inches. If the wheel makes 10 complete rotations, how far does the bike travel?

8. The wheels on William’s bike are 20 inches in diameter. He rode for 78.5 feet. How many times did his tires rotate?

Estimating Area

9. Estimate the area of Alberta in square miles. Show your reasoning.

10. Circle A has a diameter of approximately 20 inches and an area of approximately 300 in2.

Circle B has a diameter of approximately 60 inches.

Could these be the area of Circle B? State yes or no and explain your reasoning.a) About 100 in2

b) About 300 in2

c) About 900 in2

d) About 2,700 in2

11. A circle’s circumference is approximately 44 cm.Complete each statement using one of these values: 7, 11, 14, 22, 88, 138, 154,

196, 380, 616.

a) The circle’s diameter is approximately ________ cm.

b) The circle’s radius is approximately ________ cm.

c) The circle’s area is approximately ________ cm2.12. Here is a picture that shows one side of a child's wooden block with a semicircle

cut out at the bottom.

a.) Find the area of the side. Explain or show your reasoning.

b.) Find the area in terms of pi.