Question

20. Solve for mZA of the triangle.
c=302
a = 289
b=344

Answer 1

`\textit{Law of Cosines}\\\\ \cfrac{a^2+b^2-c^2}{2ab}=\cos(C)\implies \cos^(-1)\left(\cfrac{a^2+b^2-c^2}{2ab}\right)=\measuredangle C \\\\[-0.35em] ~\dotfill\\\\ \cos^(-1)\left(\cfrac{302^2+344^2-289^2}{2(302)(344)}\right)=\measuredangle A \implies \cos^(-1)\left(\cfrac{ 126019 }{ 207776 }\right)=\measuredangle A \\\\\\ \cos^(-1)(0.6065137) \approx \measuredangle A \implies 52.66^o \approx \measuredangle A`

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