Respuesta :
- 65° if parallelogram
- 115° if trapezoid
Solution to the problem
Since no diagram attached there are two possible options.
Option 1
The quadrilateral is parallelogram.
In this case ∠A and ∠D sum up to 180°, therefore:
- ∠ADC = 180° - 115° = 65°
Option 2
The quadrilateral is isosceles trapezoid.
In this case ∠A is congruent with ∠D, therefore:
- ∠ADC = ∠A = 115°