Given a + b + c + d = 0, which of the following statements are correct : (a) a, b, c, and d must eac

Given a + b + c + d = 0, which of the following
statements are correct :
(a) a, b, c, and d must each be a null vector,
(b) The magnitude of (a + c) equals the magnitude of
( b + d),
(c) The magnitude of a can never be greater than the
sum of the magnitudes of b, c, and d,
(d) b + c must lie in the plane of a and d if a and d are
not collinear, and in the line of a and d, if they are
collinear ?
#ncert
#ncertphysicsclass11