Cosine Rule Problems - Solve Arbitrarily Chosen Triangles

[nDever]

Hey,

If I wanted to make up problems that are solved using the law of cosines, shouldn't it work out even if I arbitrarily choose side a, b, and θ? After all, any two sides and an angle between them form a triangle. Correct?

 

[dacruick]

Yes correct. I'm curious to know why you think choosing sides a b and theta wouldn't give you an answer for c.

 

[mathman]

You're OK as long as the angle is < 180 deg.

 

[dacruick]

You're OK as long as the angle is < 180 deg.

Even then you'd just have a triangle in the other direction. You would just have to change a sign(no pun intended).