Its really not getting through. Could someone help?

5.64cm. The radius of a circle of area 100cm² shown in the image is r = 5.64cm.
In order to solve this exercise, we need to know that the area of a circle is A = π r². We have to clear r in the equation of the area of a circle.
We obtain [tex]r=\sqrt{\frac{A}{\pi}[/tex]
Solving the equation above with A = 100cm²:
[tex]r=\sqrt{\frac{100cm^{2} }{\pi}[/tex]
[tex]r=5.64cm[/tex]