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
75.36
75.36
37.68
37.68
18.84
18.84
452.16
The correct formula to find the approximate circumference of a circle is C = 2πr.
Substituting the given radius of 12 into the formula, we get C = 2π(12) = 24π.
Using the approximate value of π as 3.14, we can calculate the circumference: 24(3.14) = 75.36.
Therefore, the correct answer is 75.36 (option A or option B).
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⋅150
upper C approximately equals 3.14 times 150

C≈2⋅3.14⋅450
upper C approximately equals 2 times 3.14 times 450

C≈3.14⋅450÷2
The correct formula to find the circumference of a circle is C = 2πr.
Substituting the given radius of 450 into the formula, we get C = 2π(450).
To calculate the circumference, we can use the value of π as 3.14.
So, the correct formula to find the approximate circumference of a circle with a radius of 450 is C ≈ 2(3.14)(450).
Therefore, the correct answer is C ≈ 2(3.14)(450) (option C).
Which formula correctly describes the proportional relationship between the circumference of a circle and the diameter?(1 point)
Responses

Cd=π
Start Fraction upper C over d End Fraction equals pi

π=dC
pi equals Start Fraction d over upper C

C=πd
upper C equals Start Fraction pi over d End Fraction

A=πr2
upper A equals pi r squared
The formula that correctly describes the proportional relationship between the circumference of a circle and the diameter is C = πd.
This formula states that the circumference of a circle (C) is equal to pi (π) times the diameter (d).
Therefore, the correct answer is C = πd (option C).
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

65.94 mi.2
65.94 mi squared

346.19 mi.2
346.19 mi squared

1,384.74 mi.2
1,384.74 mi squared

131.88 mi.2
131.88 mi squared
The correct formula to find the area of a circle is A = πr^2, where A represents the area and r represents the radius.
Given that the diameter is 21 miles, we can find the radius by dividing the diameter by 2. So, the radius (r) is 21/2 = 10.5 miles.
Now, we can calculate the area using the formula. Plugging in the value of π as 3.14, we have A = 3.14(10.5)^2.
Calculating the square of 10.5 and multiplying by 3.14, we get A ≈ 346.185.
Rounded to the nearest hundredth, the area of the circle with a diameter of 21 miles is approximately 346.19 mi² (option B).