Question

Which is the best estimate of the circumference of this circle?

A. 1.5 units

B. 9 units

C. 3 units

D. 30 units

Answer 1

B 9 units

C = πd ( where d is the diameter )

here r = 1.5 ⇒ d = 2 × 1.5 = 3

as an estimate, approximate π to 3

C = 3 × 3 = 9 ← is the best estimate

Answer 2

Circumference is 9 units.

Explanation:

According to the formula of circumference

Circumference =
`2\pi* (radius of circle)`

Given, Radius i.e. r = 1.5 units

Circumference =
`2*(22)/(7) * 1.5`

=
`(660)/(70)`

= 9.43 units

Therefore, the best estimate of the circumference of this circle is 9 units.