3. Найдите $$\angle CBE$$

Дано:

• \[ \triangle ABC \]
• \[ AC = CB \]
• \[ \angle ADB = 90^{\circ} \]
• \[ \angle BAD = 20^{\circ} \]

Решение:

1. \[ \triangle ABC \] — равнобедренный, так как \[ AC = CB \].
2. \[ \angle ABC = \angle BAC = 20^{\circ} \]
3. \[ \angle ACB = 180^{\circ} - 20^{\circ} - 20^{\circ} = 140^{\circ} \]
4. \[ \angle CBE \] — развернутый угол, \[ \angle CBE = 180^{\circ} \]
5. \[ \angle ABC = 20^{\circ} \]
6. \[ \angle ACB = 140^{\circ} \]
7. \[ \angle CBE = ? \]

Ответ: $$180^{\circ}$$