Explicație pas cu pas:
[tex]AC² = AB² + BC² - 2×AB×BC×cos(B) = {7}^{2} \times {6}^{2} - 2 \times 7 \times 6 \cos(45) = 85 - 42 \sqrt{2} [/tex]
[tex]AC = \sqrt{85 - 42 \sqrt{2} } [/tex]
[tex]AB²=BC²+AC²-2 \times BC \times AC \times \cos(C) = {5}^{2} + {4}^{2} - 2 \times 5 \times 4 \times \cos( \frac{\pi}{6} ) = 41 - 20 \sqrt{3} [/tex]
[tex]AB = \sqrt{41 - 20 \sqrt{3} } [/tex]
