Question 1204849
given sides:

{{{a=6.0}}}
{{{b=7.0}}}
{{{c=8.0}}}

recall: The longest side in a triangle is opposite the largest angle.

so, it will be angle {{{gamma}}}


Solution: using Law of Cosine


{{{ gamma=cos^-1((a^2+b^2-c^2)/(2ab))}}}

{{{ gamma=cos^-1((6.0^2+7.0^2-8.0^2)/(2*6.0*7.0))}}}≈{{{75.52249}}}°