Suppose a triangle has sides a, b, and c, and let (theta) be the angle opposite the side of length a. If cos (theta)

Question

Suppose a triangle has sides a, b, and c, and let (theta) be the angle opposite the side of length a. If cos (theta) < 0, what must be true?

Please explain. Thank you!

kj4uts · Answer

attachment

anonymous · Answer

if cos theta < 0, then it is negative.
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cos(theta) = adjacent side/hypotenuse.

If cosine is negative, then it's not in quadrant 4.

anonymous · Answer

as for what is true, I can't help you with that sorry.  Either side a, c, or both are negative.  side c is always the largest side, however.

anonymous · Answer

If c is the hypotenuse,

anonymous · Answer

*sorry, either sides b or c are negative

anonymous · Answer

*or both

jim_thompson5910 · Answer

Law of Cosines
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