In the given circle, angle ACB = 90 degrees. Find the value of x (angle ADB).

1. Identify the given information:

• Inscribed angle ACB = 90 degrees.
• Angle x (ADB) is to be found.

2. Recognize the property of an inscribed angle subtending a semicircle:

• An inscribed angle that subtends a diameter (and thus a semicircle) is a right angle (90 degrees).
• Since angle ACB is 90 degrees, AB must be a diameter of the circle.

3. Recall the property of inscribed angles subtended by the same arc:

• Inscribed angles that subtend the same arc are equal.

4. Apply the property:

• Both angle ACB and angle ADB subtend the arc AB.
• Therefore, angle ADB = angle ACB.
• x = 90 degrees.

Ответ: 90°