Circumference & Area of Circles Quick Check
1 of 51 of 5 Items
Question
Which of the following uses the correct formula to find the approximate circumference of a circle that has a radius of 12? Use 3.14 for π and express your answer to the hundredths place.(1 point)
Responses
18.84
18.84
37.68
37.68
75.36
75.36
452.16
9 answers
37.68
Circumference & Area of Circles Quick Check
2 of 52 of 5 Items
Question
Which of the following uses the correct formula to find the approximate circumference of a circle that has a radius of 450?(1 point)
Responses
C≈3.14⋅4502
upper C approximately equals 3.14 times 450 squared
C≈3.14⋅450÷2
upper C approximately equals 3.14 times 450 divided by 2
C≈2⋅3.14⋅450
upper C approximately equals 2 times 3.14 times 450
C≈3.14⋅150
upper C approximately equals 3.14 times 150
2 of 52 of 5 Items
Question
Which of the following uses the correct formula to find the approximate circumference of a circle that has a radius of 450?(1 point)
Responses
C≈3.14⋅4502
upper C approximately equals 3.14 times 450 squared
C≈3.14⋅450÷2
upper C approximately equals 3.14 times 450 divided by 2
C≈2⋅3.14⋅450
upper C approximately equals 2 times 3.14 times 450
C≈3.14⋅150
upper C approximately equals 3.14 times 150
C≈2⋅3.14⋅450
upper C approximately equals 2 times 3.14 times 450
upper C approximately equals 2 times 3.14 times 450
Circumference & Area of Circles Quick Check
3 of 53 of 5 Items
Question
Which formula correctly describes the proportional relationship between the circumference of a circle and the diameter?(1 point)
Responses
C=πd
upper C equals Start Fraction pi over d End Fraction
π=dC
pi equals Start Fraction d over upper C
A=πr2
upper A equals pi r squared
Cd=π
Start Fraction upper C over d End Fraction equals pi
3 of 53 of 5 Items
Question
Which formula correctly describes the proportional relationship between the circumference of a circle and the diameter?(1 point)
Responses
C=πd
upper C equals Start Fraction pi over d End Fraction
π=dC
pi equals Start Fraction d over upper C
A=πr2
upper A equals pi r squared
Cd=π
Start Fraction upper C over d End Fraction equals pi
C=πd
upper C equals π times d
upper C equals π times d
Use the correct formula to find the area of a circle if the diameter is 21 mi. Round to the nearest hundredths place. Use 3.14 for π .(1 point)
Responses
1,384.74 mi.2
1,384.74 mi squared
346.19 mi.2
346.19 mi squared
131.88 mi.2
131.88 mi squared
65.94 mi.2
Responses
1,384.74 mi.2
1,384.74 mi squared
346.19 mi.2
346.19 mi squared
131.88 mi.2
131.88 mi squared
65.94 mi.2
To find the area of a circle, we use the formula A = πr^2, where r is the radius. Since the diameter is given, we first need to find the radius by dividing the diameter by 2.
Radius (r) = Diameter / 2
Radius = 21 mi / 2
Radius = 10.5 mi
Now we can use the formula for the area:
A = π(10.5)^2
A = 3.14 * 110.25
A ≈ 346.19 mi^2
Therefore, the correct answer is:
346.19 mi^2
Radius (r) = Diameter / 2
Radius = 21 mi / 2
Radius = 10.5 mi
Now we can use the formula for the area:
A = π(10.5)^2
A = 3.14 * 110.25
A ≈ 346.19 mi^2
Therefore, the correct answer is:
346.19 mi^2
Circumference & Area of Circles Quick Check
5 of 55 of 5 Items
Question
Which of the following is the correct formula for finding the area of a circle?(1 point)
Responses
A=πr2
upper A equals pi r squared
A=2πr
upper A equals 2 pi r
A=C2÷4πA=πd2
upper A equals upper C squared divided by 4 pi upper A equals pi d squared
A=πd
5 of 55 of 5 Items
Question
Which of the following is the correct formula for finding the area of a circle?(1 point)
Responses
A=πr2
upper A equals pi r squared
A=2πr
upper A equals 2 pi r
A=C2÷4πA=πd2
upper A equals upper C squared divided by 4 pi upper A equals pi d squared
A=πd
A=πr^2
upper A equals π times r squared
upper A equals π times r squared
1 answer