Recall following property of radicals:
[tex]\sqrt[]{a\cdot b}=\sqrt[]{a}\cdot\sqrt[]{b}[/tex]Since 28 can be factorized as:
[tex]2^2\cdot7[/tex]Use the property previoulsy mentioned to rewrite the square root of 28:
[tex]\begin{gathered} \sqrt[]{28}=\sqrt[]{2^2\cdot7} \\ =\sqrt[]{2^2}\cdot\sqrt[]{7} \\ =2\cdot\sqrt[]{7} \end{gathered}[/tex]Therefore, the simplest radical form of the square root of 28, is:
[tex]2\cdot\sqrt[]{7}[/tex]