Question

Question 3 (10 points)

(05.04 MO
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

Explanation:

Part A

Circumference formula:

• C = 2πr = πd

Find π:

• 25.12 = 8π ⇒ π = 25.12/8 ⇒ π = 3.14
• 9.42 = 3π ⇒ π = 9.42/3 ⇒ π = 3.14

Part B

Area formula:

• A = πr² = πd²/4

Find π:

• 50.24 = π*8²/4 ⇒ 50.24 = 16π ⇒ π = 50.24/16 ⇒ π = 3.14
• 7.065 = π*3²/4 ⇒ 7.065 = 9π/4 ⇒ π = 4*7.065/9 ⇒ π = 3.14

Part C

• The value of π is same - 3.14 from each case we have