Question 478552
A triangle has sides of length 5,8,and 10. What is the measure of its largest angle?
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It's opposite the longest side.
Use the Cosine Law:
{{{c^2 = a^2 + b^2 - 2ab*cos(C)}}}
{{{10^2 = 5^2 + 8^2 - 5*8*cos(C)}}}
cos(C) = (100 - 89)/-40 = -11/40
C = ~ 105.96 degs