4) Given angle is 160 degrees. Find angle ABC.

The diagram shows an inscribed angle $$\angle ABC$$. The value 160 degrees is indicated as the measure of the arc AC.

The formula relating an inscribed angle to its intercepted arc is:

$$\angle ABC = \frac{1}{2} \times \text{measure of arc } AC$$

Given that the measure of arc AC is 160 degrees:

$$\angle ABC = \frac{1}{2} \times 160^\circ = 80^\circ$$.

The text below the diagram confirms that $$\angle ABC$$ is an inscribed angle.

Ответ: 80°