ANSWER:
It is clear that BD is the diameter of the circle.
Also, we know that the angle in a semicircle is a right angle.
i.e., ∠ BAD = 90 °
Now, considering the Δ BAD, we have:
∠ ADB + ∠ BAD + ∠ ABD = 180 ° (Angle sum property of a triangle)
⇒ ∠ ADB + 90 ° + 35 ° = 180 °
⇒ ∠ ADB = (180 ° - 125 ° ) = 55 °
Angles in the same segment of a circle are equal.
Hence, ∠ ACB = ∠ ADB = 55 °