Answer:
∠ A = 50°
Step-by-step explanation:
The angle at the centre COB is twice the angle at the circumference CDB
∠ COB = 2 × 65° = 130°
The angles ACO = ABO = 90° ( angle between radius and tangent )
The sum of the angles in quadrilateral ABOC = 360° thus
∠ A = 360° - (90 + 90 + 130)° = 360° - 310° = 50°
