SOLUTION: If the area of a circle is a whole number, which of the following could be the circumference? A) 3✔️pi B) 2✔️pi C) 2 D) 2pi E) pi✔️2

Algebra ->  Square-cubic-other-roots -> SOLUTION: If the area of a circle is a whole number, which of the following could be the circumference? A) 3✔️pi B) 2✔️pi C) 2 D) 2pi E) pi✔️2      Log On


   



Question 1043873: If the area of a circle is a whole number, which of the following could be the circumference?
A) 3✔️pi
B) 2✔️pi
C) 2
D) 2pi
E) pi✔️2

Answer by advanced_Learner(501) About Me  (Show Source):
You can put this solution on YOUR website!
just substitute and see
C=2pi%2Ar
A=pi%2Ar%5E2
only B give whole number area of circle.
2%2Asqrt%28pi%29=2pi%2Ar
2%2Asqrt%28pi%29%2F%282%2Api%29=r
square both sides
4%2A%28pi%29%2F%284%2A%28pi%29%5E2%29=r%5E2
area is A=pi%2Ar%5E2
pi4%2A%28pi%29%2F%284%2A%28pi%29%5E2%29=Area+of+circle
which gives A=1 whole number area of circle,do for the rest.
A gives area of 9%2F4
B gives area of 1
C gives area of 1%2F%28pi%29%7D%7D%0D%0A%0D%0A%0D%0AD+gives+area+of+%7B%7B%7Bpi

E gives pi%2F2
comment is welcome