Question

What is the exact circumference of the circle?

A. 10 feet
B. 20 feet
C. 40 feet <-- my answer
D. 60 feet

Am I right

Answer 1

\[c= 2\pi*r\]

Answer 2

not exactly to get the circumference you multiply the diameter by pi

Answer 3

of course you do

Answer 4

the circumference is the perimeter of the circle (area)

Answer 5

\[c= 2\pi*r\] is the correct formula for the circumference of this circle. Please look carefully at the illustration you've provided. What is the radius of this circle?

Answer 6

Note that CoralReef's approach is completely valid also. Take your pick, @♥Lila♥