Question

Which of the following is the best estimate of the circumference of a circle that has a diameter of 7 feet?

11 ft
14 ft
42 ft
21 ft

Answer 1

Circumference of a circle = (3.14)d
d = 7

C = (3.14)(7)

C = 21.99

So the answer is D. 21 ft

Answer 2

The best estimate of the circumference of a circle is 21 ft.

Explanation:

Formula

`Circumference\ of\ a\ circle = 2\pi r`

Where r is the radius of a circle.

As given

Diameter of 7 feet .

`Radius = (7)/(2)`

Radius = 3.5 feet

As

`\pi = 3.14`

Put in the formula

`Circumference\ of\ a\ circle = 2* 3.14* 3.5`

Circumference of a circle = 21.98 ft .

Therefore the best estimate of the circumference of a circle is 21 ft.