Question

Circle A has a diameter of 8 inches, a circumference of 25.12 inches, and an area of 50.24 square inches. The diameter of circle B is 3 inches, the circumference is 9.42 inches, and the area is 7.065 square inches.

Part A: Using the formula for circumference, solve for the value of pi for each circle. (4 points)

Part B: Use the formula for area and solve for the value of pi for each circle. (4 points)

Part C: What observation can you make about the value of pi for circles A and B? (2 points)​

Answer 1

Hi, it says "Using the formula for circumference, "

Do you know the formula for find the circumference of a circle ?

Answer 2

multiply the diameter of the circle with π (pi). The circumference can also be calculated by multiplying 2×radius with pi (π=3.14).

Answer 3

correct but its can aslo be \[ C= 2 \pi r \]

we use the Greek letter π because if we tried to write out the actual number, it goes on forever.

Answer 4

now they say
Circle A has a diameter of 8 inches
what is the radius of circle A? any idea ?

Answer 5

r=4in
d Diameter =8 in

Answer 6

pi * 8 = 25.12
now "solve for pi" by dividing both sides by 8
pi= 24.12/8
what do you get?

Answer 7

Part A

Circle A

Circumference = 2πr
25.12 = 2π(4)
25.12 = 8π
Divide both side by 8
3.14 = π

Circle B

Circumference = 2πr
9.42 = 2π(3/2)
9.42 = 3π
Divide both side by 3
3.14 = π

Part B

Circle A

A = πr²
50.24 = π(4)²
50.24 = 16π
Divide both side by 16
3.14 = π

Circle B

A = πr²
7.065 = π(3/2)²
7.065 = 9π/4
Divide both side by 9/4
3.14 = π

Part C

He/She used exactly 3.14 for the value of pi in circle A and B to get the circumference and the area.