SOLUTION
[tex]2 {r}^{2} = 18 \\ {r}^{2} = \frac{18}{2} \\ {r}^{2} = 9 \\ \sqrt{ {r}^{2} } = \sqrt{9} \\ r = ± \: 3[/tex]
ANSWER
[tex] \large \boxed{r = \red3 \: \: , \red{- 3}}[/tex]
[tex] \overbrace{ \underbrace{ \tt{} \purple{ \: \: Stay \: safe \: and \: God \: bless \: you! \: \: }}}[/tex]
