Question 1101467: Find the largest angle in a triangle with sides 6.0 cm, 7.0 cm, and 8.0 cm. Found 3 solutions by Alan3354, stanbon, ikleyn:Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website! Find the largest angle in a triangle with sides 6.0 cm, 7.0 cm, and 8.0 cm.
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It's opposite the longest side.
Use the Cosine Law.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website! Find the largest angle in a triangle with sides 6.0 cm, 7.0 cm, and 8.0 cm.
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The angle opposite the largest side is the largest angle.
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a^2 = b^2 + c^2 - 2bc*Cos(A)
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Cos(A) = [b^2+c^2-a^2]/(2bc)
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Cos(A) = [6^2+7^2-8^2]/(2*6*7) = -0.9167
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A = arccos(-0.9167) = 156.44 degrees
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Cheers,
Stan H.
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The angle opposite the largest side is the largest angle.
a^2 = b^2 + c^2 - 2bc*Cos(A)
Cos(A) = [b^2+c^2-a^2]/(2bc)
Cos(A) = (6^2+7^2-8^2)/(2*6*7) = .
A = arccos(1/4) = 75.56 degrees (approximately).