Answer:
when it's maintain supplimentary , it means that the sum of the angles given is 180° , In this case let one of the angle be x and the other is given as 125° .
therefore
125° + x = 180°
x = 180° - 125° = 55°
the compliment of x is the angle which when added to x givens 90° , Let the angle be y.
therefore
x + y = 90°
y = 90° - x = 90° - 55° = 35°
35° is the answer