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⋅150
upper C approximately equals 3.14 times 150
C≈3.14⋅4502
upper C approximately equals 3.14 times 450 squared
C≈2⋅3.14⋅450
upper C approximately equals 2 times 3.14 times 450
C≈3.14⋅450÷2
C≈3.14⋅450
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
A=πr2
upper A equals pi r squared
π=d/C
pi equals Start Fraction d over upper C
Cd=π
C=πd
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
65.94 mi.2
65.94 mi squared
346.19 mi.2
346.19 mi squared
131.88 mi.2
A=πr^2
r=d/2 = 21/2 = 10.5
A = 3.14*(10.5)^2 = 346.19 mi^2
Therefore, the correct answer is 346.19 mi^2.
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=πd
upper A equals pi d
A=C2÷4πA=πd2
A=πr^2
(upper A equals pi r squared)