Final answer:
The radius of Big Ben's clock is 11.5 feet, and the circumference approximates 72.25666 feet when using the formula C = 2πr.
Step-by-step explanation:
The clock tower of Big Ben has a diameter of 23 feet. To find the radius, we divide the diameter by 2, since the radius is half the length of the diameter. Therefore, the radius of Big Ben's clock is 23 feet ÷ 2 = 11.5 feet.
The circumference of a circle can be calculated using the formula C = 2πr, where C is the circumference and r is the radius. Using the radius of Big Ben's clock (11.5 feet), the circumference would be C = 2 × 3.14159 × 11.5 feet ≈ 72.25666 feet.