The arc measure of AD in degrees is 43 degrees.
Step-by-step explanation:
⇒ (7x+1)° + 90° + (9x-7)° = 180°
⇒ 16x + 84° = 180°
⇒ 16x = 96°
⇒ x = 96/16
x = 6
Substitute x=6 for angle ∠APD = (7x+1)°
∠APD = 7(6)+1 = 43°
The arc measure of AD in degrees = 43 degrees.