The area of circle c is 81 pi . if the radius of the circle is doubled, what is the circumference of the new circle ?
please answer and explain
3 answers
162 pi
my answer is 162 pi too, but the answer is
a. 18 pi
b. 36 pi
c. 36 pi^2
d. 324 pi
e. 324 pi^2
a. 18 pi
b. 36 pi
c. 36 pi^2
d. 324 pi
e. 324 pi^2
if a = 81pi, r = 9
if r = 18, c = 36pi
if r = 18, c = 36pi
2 answers