How would i find r? i need this question to be longer to send so i'm adding extra characters

To find r, you can multiply both sides by πr²


You would then get:
513πr² = 79,000

Then to isolate r, you can divide 513π on both sides.

(513πr²)/(513π) = 79,000/(513π)
r² = 79,000/(513π)

To finally get r, you can take the square root of both sides.