S.102 T.275


11=\frac{1}{2}\cdot8{,}8\cdot5{,}0\cdot\sin\alpha
11=22\cdot\sin\alpha
\sin\alpha=0{,}5
\alpha=30
x^2=8{,}8^2+5^2-2\cdot8{,}8\cdot5\cdot\cos30
x=\pm\sqrt[]{8{,}8^2+5^2-2\cdot8.8\cdot5\cdot\cos30}
x=5{,}121...\approx5{,}1\left(cm\right)
V:\ x\approx5{,}1cm