Question

What is the approximate circumference of a circle with a radius of 20 inches? Use π ≈ 3.14. A. 125.6 inches B. 251.2 inches C. 120 inches D. 62.8 inches

Answer 1

For any circle, the circumfrence $C=2\pi r=\pi d$ where r is the radius and d is the diameter.
Use 20 inches for our radius in the formula $C=2\pi r$.
$C=2\pi \times20$
Using π ≈ 3.14...
$C\approx2\times3.14\times20$
$C\approx6.28\times20$
$\boxed{C\approx125.6\ inches}$

Answer 2

 C = pi*d = 2*pi*r
C = 2*pi*20 = 3.14*40 = 125.6in

A