Calculate Circle Radius: Converting 25 cm² Area Using A = πr²

Because the area formula is $A = \pi r^2$, not $A = \pi r$! The radius is squared in the formula, so you need to take the square root after dividing by π.

It depends on what your teacher prefers! $\frac{5}{\sqrt{\pi}}$ is mathematically correct, but you could also write it as $\frac{5\sqrt{\pi}}{\pi}$ if rationalized form is required.

Square your radius and multiply by π - you should get back to 25! Also, since the area is 25 cm², the radius should be roughly between 2-3 cm (since π ≈ 3.14).

That's fine too! $\frac{5}{\sqrt{\pi}} \approx 2.82$ cm. Just remember that the exact answer $\frac{5}{\sqrt{\pi}}$ is more precise than any decimal approximation.

Because radius represents a physical distance, which must be positive! Even though $r^2 = \frac{25}{\pi}$ has two mathematical solutions (±), we only use the positive one for geometry.