Question

ABCD is a parallelogram then ∠A – ∠ C = ________ degrees

Answer 1

angle A and angle C are opposite sides of a parallelogram. So they are equal.
Therefore Angle A - Angle C = 0

Hope this helps you...

Answer 2

In a parallelogram opposite angles are equal.Here A and C are the opposite angles.
A-C
A-A=0 (Opposite angles are equal of parallelogram)
Hence,the answer is 0