Question

Can you use the Law of Cosines in the triangle below? Why or why not?
triangle whose sides measure 15, 21, and 22 units long

Answer 1

What are YOUR thoughts about this?
Does this appear to be a right triangle, or not (not that it matters here)?

Answer 2

it doesn't look like a right triangle

Answer 3

If this is not a right triangle, then the Pythagorean Theorem doesn't apply. However, I see no reason why we couldn't apply the Law of Cosines.

\[a ^{2}=b ^{2}+c ^{2}-2bc*\cos A\] where side a is opposite Angle A. What else do you need to know to complete your answer to this question?