<PRE><B>Question 286259</B>
The three sides of a triangle are 7, 24, and 30 units long. Is the triangle acute, right or obtuse? You must support your answer with computations.
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Use the Law of Cosines:
cos(A) = (7^2 + 24^2-30^2)/(2*7*24) = -0.81845
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A = cos^-1(-0.81845) = 144.94 degrees
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cos(B) = (30^2+7^2-24^2)/(2*30*7)
cos(B) = 0.8881
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B = cos^-1(0.8881) = 27.37 degrees
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cos(C) = (30^2+24^2-7^2)/(2*30*24) = 0.9910
C = cos^-1(0.9910) = 7.70 degrees
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Cheers,
Stan H.</PRE>