Which of the following expressions correctly shows the relationship between the circumference and the area of a circle?(1 point)
Responses
C=2πr
upper C equals 2 pi r
A=πr2
upper A equals pi r squared
Cd=π
Start Fraction upper C over d End Fraction equals pi
C2=4πA
C=2πr
If C=12π , what is the area of the circle? (1 point)
Responses
36π
36 pi
12π
12 pi
24π
24 pi
144π
If C=12π, the correct formula to use is C=2πr, so we can solve for r: 12π = 2πr → r = 6. Then, we can calculate the area using the formula A=πr^2: A = π(6)^2 = 36π.
Therefore, the area of the circle is 36π.
Which chart is correctly developed with the circumference and the area of a circle with a radius of 5 cm?(1 point)
Responses
Radius Circumference Area
5 cm 15.7 cm 19.63 cm2
Radius Circumference Area 5 cm 15.7 cm 19.63 cm squared
Radius Circumference Area
5 cm 62.8 cm 314 cm2
Radius Circumference Area 5 cm 62.8 cm 314 cm squared
Radius Circumference Area
5 cm 78.5 cm 31.4 cm2
Radius Circumference Area 5 cm 78.5 cm 31.4 cm squared
Radius Circumference Area
5 cm 31.4 cm 78.5 cm2
To develop the correct chart, let's use the formulas:
Circumference (C) = 2πr
Area (A) = πr^2
Given the radius (r) is 5 cm:
For Circumference (C):
C = 2π(5) = 10π ≈ 31.4 cm
For Area (A):
A = π(5)^2 = 25π ≈ 78.5 cm^2
So the correct chart is:
Radius Circumference Area
5 cm 31.4 cm 78.5 cm^2
Which formula is used to find the area of a circle when given the radius?(1 point)
Responses
A=r
upper A equals r
A=2r
upper A equals 2 r
A=r2
upper A equals r squared
A=d2
A=πr^2
The correct formula to find the area of a circle when given the radius is A=πr^2.
Which formula is used to find the circumference of a circle when the radius is given?(1 point)
Responses
C=r2
upper C equals r squared
C=r
upper C equals r
C=2d
upper C equals 2 d
C=2r
C=2πr
The correct formula to find the circumference of a circle when the radius is given is C=2πr.