In the problem, the segment AD is the diameter. Hence, we can say that the angle formed by segment AD is 180°.
Since we ask what is the angle of ATB, then we can directly sum the angles of BTC and angle of CTD, the result of this summation will be subtracted to 180°. The solution is shown below:
∠ATB = 180 -(∠BTC + ∠CTD)
∠ATB=180°-(56°+32°)
∠ATB=92°
The answer for the angle of ATB is 92°.