SOLUTION: Hi. I'm wondering if I am on the righ track with this one.. In triangle ABC we have the sides a=2.5, b=5.0, c=2.0 Find the cosine of the angle B. I understand that use the

Algebra ->  Trigonometry-basics -> SOLUTION: Hi. I'm wondering if I am on the righ track with this one.. In triangle ABC we have the sides a=2.5, b=5.0, c=2.0 Find the cosine of the angle B. I understand that use the       Log On


   

Question 306140: Hi. I'm wondering if I am on the righ track with this one..
In triangle ABC we have the sides a=2.5, b=5.0, c=2.0
Find the cosine of the angle B.
I understand that use the cosine function.. cosB=length of adjacent side/length of hypotenuse.
I am just wondering how to know which side is the hypotenuse and which is the adjacent.
Thank you
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
there is a problem with the problem...

"b" is larger than the sum of "a" and "c"
___ this means that the sides of the triangle cannot close up, the triangle doesn't exist


also, if a triangle is not a right triangle (check by using Pythagoras); you will need the Law of Cosines to find the angles