In a parallelogram ABCD, AB = 54, BC = 78, AC2 — BD2 = 8,168. Find the following.
a. the angles ABCD
b. the diagonals AC and BD
c. the angles between the diagonals AC and BD
I have no idea how to start solving these questions.
a. Angles A and C are 40 degrees, angle B and D are 140 degrees.
b. AC = 90, BD = 68
c. The angle between the diagonals is 20 degrees.
Thank you for your answers.
Could you explain how you got those answers, please?