[tex]b)\\\\a=2,\ \ b=?\ \ c=2\sqrt{5}\\\\a^2+b^2=c^2\\\\b^2=c^2-a^2\\\\b=\sqrt{c^2-a^2}\\\\b =\sqrt{(2\sqrt{5})^2-2^2}\\\\b =\sqrt{20-4} \\\\b=\sqrt{16}\\\\b=4[/tex]
[tex]c)\\\\a=?,\ \ b=6\ \ c=2\sqrt{13}\\\\a^2+b^2=c^2\\\\a^2=c^2-b^2\\\\a=\sqrt{c^2-b^2}\\\\a =\sqrt{(2\sqrt{13})^2-6^2}\\\\a =\sqrt{52-36} \\\\a=\sqrt{16}\\\\a=4[/tex]
