What is the angle between two component vectors with magnitudes 8 and 10?

[findlayxc]

Two component vectors with magnitude of 8 and resultant magnitude of 10. What must be the angle between the two component vectors?

I really don't know where to start on this. Any help would be greatly appreiated!

P.S. need by tomorrow!

 

[NoMoreExams]

Do you have any formulas to compute magnitude of the component vectors and the resultant magnitude?

 

[findlayxc]

found the answer somewhere else, thanks any way.