Question 199242
We use cosine law to solve this problem.
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{{{a^2=b^2 + c^2 -2bc*cos A}}}
={{{8^2 + 10^2 -2*8*10*cos 74}}}
={{{64+100-160cos 74}}}
=120
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So, {{{a=sqrt(120)=10.9}}}