Question

In a Parallelogram ABCD A(1,2), B(7,3), C. (8,9) are the Points
a. find D?
b. Prove that the Sum of the Squares88 the diagonals is equal to the Sum of the Square of the sides?​

Answer 1

Answer:

(

if ABCD are not in order there are three possible coordinates for D-1-(14,10);2-(0,-4)3-(2,8)