Answer
$r*\sqrt{\pi} = {\sqrt A}/{2\pi}$
Work Step by Step
$r = \frac{\sqrt A}{\sqrt{4\pi}}$
$r = \frac{\sqrt A}{2\sqrt{\pi}}$
$r*\sqrt{\pi} = \frac{\sqrt A}{2\sqrt{\pi}}*\sqrt{\pi}$
$r*\sqrt{\pi} = {\sqrt A}/{2\pi}$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.