Final answer:
Angle ∠d is the linear pair of angle ∠dga.
Step-by-step explanation:
A linear pair of angles consists of two adjacent angles that form a straight line. In this case, angle ∠dga is the given angle, so we need to find the angle that when added to angle ∠dga forms a straight line. This angle is angle ∠d, which is opposite to angle ∠a.
Therefore, angle ∠d is the linear pair of angle ∠dga.
Answer: a) Angle ∠d