Question

A cylindrical barrel has a diameter of 18

inches. Which of the following is the best estimate
of the circumference of the barrel in feet?
A. 10 ft
B. 2 ft
C. 5 ft
D. 1 ft​

Answer 1

C. 5 ft

Explanation:

Radius = 18/2 = 9 in ÷ 12 = 0.75 ft

Circumference = 2 × 3.14 × 0.75

= 4.71 ft

From the options, 5 ft is the closest

Answer 2

C. 5 ft

Explanation:

The diameter is 18 inches. Lets change that to feet

1 ft = 12 inches

18 inches * 1 ft/12 inches = 1.5 ft

The circumference is given by

C = pi *d

C = 3.14 * 1.5

C =4.71 ft