Let ` vec a , vec b , vec c , vec d` be the position vectors of the four distinct points `A , B , C , Ddot` If ` vec b- vec a= vec c- vec d ,` then show that `A B C D` is parallelogram.

Let vec a , vec b , vec c , vec d be the position vectors of the four distinct points A , B , C , Ddot If vec b- vec a= vec a- vec d , then show that A B C D is parallelogram.

Let vec a , vec b , vec c , vec d be the position vectors of the four distinct points A , B , C , Ddot If vec b- vec a= vec c- vec a , then show that A B C D is parallelogram.

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

If P is a point and A B C D is a quadrilateral and vec A P+ vec P B+ vec P D= vec P C , show that A B C D is a parallelogram.

If P is a point and A B C D is a quadrilateral and vec A P+ vec P B+ vec P D= vec P C , show that A B C D is a parallelogram.

If vec a ,\ vec b ,\ vec c are position vectors o the point A ,\ B ,\ a n d\ C respectively, write the value of vec A B+ vec B C+ vec A Cdot

If vec a , vec b , vec ca n d vec d are the position vectors of the vertices of a cyclic quadrilateral A B C D , prove that (| vec axx vec b+ vec bxx vec d+ vec d xx vec a|)/(( vec b- vec a)dot( vec d- vec a))+(| vec bxx vec c+ vec cxx vec d+ vec d xx vec b|)/(( vec b- vec c)dot( vec d- vec c))=0dot

If vec a , vec b , vec c , vec d are the position vector of point A , B , C and D , respectively referred to the same origin O such that no three of these point are collinear and vec a + vec c = vec b + vec d , than prove that quadrilateral A B C D is a parallelogram.

If vec a , vec b , vec c , vec d are the position vector of point A , B , C and D , respectively referred to the same origin O such that no three of these point are collinear and vec a + vec c = vec b + vec d , than prove that quadrilateral A B C D is a parallelogram.

If vec a ,\ vec b ,\ vec c are three non coplanar vectors such that vec d dot vec a= vec d dot vec b= vec d dot vec c=0, then show that d is the null vector.