If |a . b| = 3 and |a × b| = 4 then the angle between a and b is

If |a+b|gt|a-b| , then the angle between a and b is

If a + b + c = 0 and |a| = 1, |b| = 1, |c| = sqrt3 ,then the angle between a and b is

If a and b are the two vectors such that |a|-3sqrt(3),|b|=4 and |a+b|=sqrt(7) , then the angle between a and b is

If (|a+b|)/(|a-b|)=1 , then the angle between a and b is

If A.B=AxxB , then angle between A and B is

If a+b+c=0 and |a|=5, |b|=3 and |c|=7 , then angle between a and b is