[tex]BCA\ jest\ rownoramienny\ wiec BA=3\\a) z\ tw\ pitagorasa\ w\ tr\ BAE\\10^{2}+3^{2}=x^{2} \\ x^{2} =109\\ x=\sqrt{109}\\ AE=\sqrt{109}\\\\b) z\ tw\ pit\ w\ tr\ ABC\\3^{2}+3^{2}=x^{2} \\ x^{2} =18\\ X=\sqrt{18}=3\sqrt{2} \\ AC=3\sqrt{2}\\ \\C)z\tw\ pit\ w\tr\ DBA\\4^{2}+3^{2}=x^{2} \\ x^{2} =25\\ x=5\\suma\ przyprostokatnych:4+3=7\\7-3=4\\odp:NIE\\[/tex]