Question

A circle has a diameter of 18 feet. Which following is closest to the l circumference of the circle?

A-28.3ft
B-56.5ft
C-113.1ft
D-245.5ft​

Answer 1

56.5 ft

Explanation:

We define the number π as the ratio between the circumference and diameter of a circle: π = c/d. Rearranging this equation gives us one for the circumference: c = πd. Using an approximation of π ≈ 3.14 and our value of d = 18 feet, we can find that c = 3.14(18) = 56.52 ft, or 56.5 ft, rounded to the nearest tenth.

Answer 2

circumference =2×pi×r

18/2=9(r)

so...2×pi×9

=54..5