Name _______________________________ Date __________________ Period __________
Giving Area of a Circle a Spin
Choose the best answer for each question after using the equation method to show your work.
Draw a picture and/or use the problem solving model if needed.
1. The diagram below models the length from the center of a wind turbine to the tip of one its blades.
Which of these is closest to the total area covered
by the blade when the turbine makes 1 revolution?
A
B
C
D
804 m
6,431 m2
402 m2
3,215 m2
2
10
7
5
3
2. Use the ruler on the STAAR Reference Materials to measure the diameter of the coin to the nearest
centimeter.
Which is closest to the area of the coin?
F
G
H
J
6 cm2
19 cm2
13 cm2
3 cm2
10
7
5
3
3. A skydiver is laying out a circular target for his next jump that has a diameter of 16 feet. Which
expression can be used to determine the area of the target?
A 2(π)(16)
B π(16)2
C 2(π)(8)
D π(8)2
10
7
5
3
4. The area of a circular garden is 254.34 ft 2. Which of the following could be the approximate diameter
of the garden?
F
G
H
J
9 feet
18 feet
40.5 feet
81 feet
10
7
5
3
5. The diameter of a video game disc is 12 cm. Which expression below represents the area of the disc?
A
B
C
D
144 π
16 π
6π
36 π
10
7
5
3
Name _______________________________ Date __________________ Period __________
6. Jillian measured the distance across a small fishpond as 24 yards. What would be a good estimate of
the area of the fishpond?
F
G
H
J
10
7
5
3
1808 yards2
452 yards2
75 yards2
151 yards2
7. A restaurant makes pizzas with 6-inch diameters and 12-inch diameters. Which of the following
statements is true?
A The area of the 12-inch pizza is twice the area of the 6-inch pizza.
B The area of the 12-inch pizza is three times the area of the 6-inch pizza.
1
C The area of the 6-inch pizza is
the area of the 12-inch pizza.
4
1
D The area of the 6-inch pizza is
the area of the 12-inch pizza.
6
10
7
5
3
8. Jake has a circle shaped deck attached to the back of his house that has a diameter of 14 feet. What
is the approximate area of the deck?
F
G
H
J
10
7
5
3
77 ft.2
154 ft.2
44 ft.2
539 ft.2
9. Marcus wants to install a circular mosaic of decorative tile on his patio. This mosaic will measure
30 feet in diameter. Which of the following is closest to the number of square feet of decorative tile
that Marcus will need to make this mosaic?
A
B
C
D
10
7
5
3
2,800 ft.2
700 ft.2
100 ft.2
200 ft.2
10. Line segment CD passes through the center of the circle shown on the coordinate grid below.
Which of the following is closest to the area of the circle?
F
G
H
J
1,256 units2
314 units2
5,024 units2
126 units2
Answer Bank:
A
B
C
D
D
G H
G
G
J
10
7
5
3
Name _______________________________ Date __________________ Period __________
Circle Swirl Homework
Find the approximate area of each circle using the equation method.
Remember to write the equation on the first line, substitute values for
variables on the second line, show work, and write the answer on the last line.
1.
2.
3.
r = 12 cm
A=
A=
A=
A=
A=
A=
A = _______ cm2
A = _______ in.2
A = ________ in.2
Choose the best answer for each question after using the equation method to show your work.
Draw a picture and/or use the problem solving model if needed.
4. The diameter of the circle that a shot-putter stands in is 7 ft. What is the approximate area of the
circle?
A
B
C
D
49 π ft2
12.25 π ft2
196 π ft2
7 π ft2
5. A cylindrical barrel has a diameter of 24.124 inches. Which of the following is the best estimate of the
circumference of the barrel in feet? (Hint: How many inches are in 1 foot?)
F
G
H
J
13 ft
2 ft
6 ft
3 ft
6. The diagram at right shows 2 circles with the same center at point F. Points E, F, and G are on line
segment DH. The diameter of the larger circle is 14 mm.
What is the radius of the smaller circle?
A
B
C
D
4 mm
7 mm
11 mm
8 mm