Answer:
C
Step-by-step explanation:
So we have the equation:
[tex]B=d\pi r^2[/tex]
And we want to solve for r.
So first, isolate the r variable. Divide both sides by dπ. So:
[tex]\frac{B}{d\pi}=\frac{d\pi r^2}{d\pi}[/tex]
The right side cancels:
[tex]\frac{B}{d\pi}=r^2[/tex]
Take the square root of both sides:
[tex]r=\sqrt\frac{B}{d\pi}[/tex]
We can rearrange the terms:
[tex]r=\sqrt\frac{B}{\pi d}[/tex]
Our answer is C.
