HELP PLEASE (:Crystal is writing a coordinate proof to show that the diagonals of a parallelogram bisect each other. She starts by assigning coordinates as given.

Answer:
Please see below.Explanation:
The coordinates of point C are (a+b,c).
The coordinates of the midpoint of diagonal ¯¯¯¯¯¯AC are (a+b2,c2).
The coordinates of the midpoint of diagonal ¯¯¯¯¯¯BD are (a+b2,c2).
¯¯¯¯¯¯AC and ¯¯¯¯¯¯BD intersect at point E with coordinates (a+b2,c2).
By the definition of midpoint, ¯¯¯¯¯¯AE≅¯¯¯¯¯¯CE and ¯¯¯¯¯¯BE≅¯¯¯¯¯¯DE.
Therefore diagonals ¯¯¯¯¯¯AC and ¯¯¯¯¯¯BD bisect each other.