Triangle

 Find AE.

Hello magenta!

Cosine law:$c^2=a^2+b^2-2ab\ cos\ \gamma$

$\overline{AE}\ ^2=3^2+5^2-2\cdot 3\cdot 5\cdot cos\ 60^{\circ}\\ \overline{AE}=\sqrt{9+25-30\cdot \frac{1}{2}}=\sqrt{19}\\ \color{blue}\overline{AE}=4.359$

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