I will be using the Law of cosine
Example: would be if a car in the dessert was traveling 4.3m one way then turn at 30 degrees and went to 7.2m another direction.
If side b = 4.3m at an angle of 30 degrees and another side c =7.2m we use the law of cosine as such.
once your answer you can now solve for side a. to do that you would need to take the square root of it.
a2=16.7057 will now be
which should give us 4.08726
round to 4.1m
I think this would be how cell phones are tracked too.