Bonsoir,

1)

[tex]BC^{2} =AB^{2} +AC^{2} \\BC^{2} =7,4^{2} +16^{2} \\BC^{2} = 54,76 + 256\\BC^{2} = 310,76\\BC = \sqrt{310,76} \\BC = 17,62838619953625[/tex]

BC ≈ 17,6

2)

[tex]BC^{2} = AB^{2} +AC^{2} \\AC^{2} = CB^{2} - AB^{2} \\AC^{2} = 7,7^{2} - 2,4^{2}\\AC^{2} = 59,29 - 5,76\\AC^{2} = 65,05\\AC = \sqrt{65,05} \\AC = 8,065358020571684[/tex]

AC ≈ 8,1

3)

[tex]BC^{2} =AB^{2} +AC^{2} \\AC^{2} =BC^{2} -AB^{2} \\AC^{2} =16,9^{2} -7,4^{2} \\AC^{2} =285,61 - 54,76\\AC^{2} = 230,85\\AC = \sqrt{230,85} \\AC = 15,19374871452072[/tex]

AC ≈ 15,1