The points A, B and C have position vectors a = ( 2, 1, 2) b= (-3, 2, 5)
c= ( 4, 5, -2) respectively with respect to a fixed origin. The point D is such that ABCD, in that order is a parallelogram.
a) Find the position vector of D
b) Fİnd the position vector of the point at which the diagonals of the parallelogram interesct
c) Calculate the angle BAC, giving your answer to the nearst tenth of a degree.
Thank you in advance! I would really appreciate it if you showed the steps.