If ` vec a , vec b , vec c`
and ` vec d`
are the position vectors of points `A , B , C , D`
such that no three of them are collinear and ` vec a+ vec c= vec b+ vec d , t h e n A B C D`
is a
a. rhombus b.
rectangle
c. square d.
parallelogram
A. rhombus
B. rectangle
C. square
D. parallelogram
