$\sqrt{17}\approx 4,12\text{H}$  

$\sqrt{8}\approx 2,83\text{F}$  

$\sqrt{\frac{1}{4}}=\frac{1}{2}=0,5\text{D}$  

$\sqrt{2}\approx 1,41\text{E}$  

$\sqrt{\frac{16}{100}}=\frac{4}{10}=0,4\text{C}$  

$-\sqrt{3}\approx -1,73\text{B}$  

$-\sqrt{25}=-5\text{A}$  

${\left(\sqrt{3}\right)}^2=\sqrt{3}\cdot \sqrt{3}=\sqrt{3\cdot 3}=3\text{G}$