Question

Find the length of side x

Answer 1

`\textit{Law of Cosines}\\\\ c^2 = a^2+b^2-(2ab)\cos(C)\implies c = √(a^2+b^2-(2ab)\cos(C)) \\\\[-0.35em] ~\dotfill\\\\ x = √(18^2+15^2~-~2(18)(15)\cos(105^o)) \implies x = √( 549 - 540 \cos(105^o) ) \\\\\\ x\approx√(549-(-139.76))\implies x\approx√(688.76)\implies {\Large \begin{array}{llll} x\approx 26.2 \end{array}}`

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