PLEASE HELP!! IM ON THE LAST QUESTIONNNN ( 30 points!)

[tex]~~~~~\pi r^2 = 513\\\\ \implies r = \sqrt{\dfrac{513}{\pi}}\\\\ \implies r= \sqrt{\dfrac{513}{3.14}}\\\\\implies r=12.78~ \text cm.}\\\\\text{Hence the radius is 12.78 cm.}[/tex]
Answer:
Step-by-step explanation:
Area of circle = πr²
[tex]\sf \boxed{r =\sqrt{ \dfrac{Area}{3.14}}}[/tex]
[tex]\sf r =\sqrt{\dfrac{513}{3.14}}\\\\r = \sqrt{163.38}\\\\r = 12.78 \ cm[/tex]