[tex] {4}^{2} + {2}^{2} = {c}^{2} \\ 16 + 4 = {c}^{2} \\ 20 = {c}^{2} \\ c = \sqrt{20} = \sqrt{ 4\times5 } = 2 \sqrt{5} [/tex]
[tex](2 \sqrt{3} {)}^{2} + {2}^{2} = {c}^{2} \\ 12 + 4 = {c}^{2} \\ 16 = {c}^{2} \\ c = 4[/tex]
[tex]2m = 20dm \\ {20}^{2} + {2}^{2} = {c}^{2} \\ 40 + 4 = {c}^{2} \\ c = \sqrt{44} = 2 \sqrt{11} [/tex]
[tex]1dm = 10cm \\ {3}^{2} + {b}^{2} = {10}^{2} \\ 9 + {b}^{2} = 100 \\ {b}^{2} = 91 \\ b = \sqrt{91} [/tex]
[tex] {a}^{2} + ( \sqrt{2} {)}^{2} = (2 \sqrt{5} {)}^{2} \\ {a}^{2} + 2 = 20 \\ {a}^{2} = 18 \\ a = \sqrt{18} = 3 \sqrt{2} [/tex]
[tex]1m = 10dm \\ {a}^{2} + {1}^{2} = {10}^{2} \\ {a}^{2} + 1 = 100 \\ {a}^{2} = 99 \\ a = \sqrt{99} = 3 \sqrt{11} [/tex]
