Step-by-step explanation:
Angles APD, DPC and CPB are supplementary. (Angles on a straight line)
Therefore Angle APD + Angle DPC + Angle CPB = 180°.
Since Angle DPC = 90° (Right angle),
Angle APD + Angle CPB = 180° - 90° = 90°.
=> (7x + 1) + (9x - 7) = 90
=> 16x - 6 = 90
=> x = 6
Hence arc measure of minor arc AD
= (7x + 1)° = [7(6) + 1]° = 43°.
