Final answer:
The measure of ∠bac is 95°. It is found by subtracting the measure of ∠abc which is 85° from the 180° that make up a straight line.
Step-by-step explanation:
The question asks for the measure of ∠bac given that the measure of ∠bcd is 120° and the measure of ∠abc is 85°. This is often referred to as an interior angles problem. Since ∠abc and ∠bac are adjacent angles that form a straight line with ∠bcd (which measures 120°), the sum of ∠abc and ∠bac must equal 180° because a straight line equals 180°. By using the known angle measure, we can calculate the measure of ∠bac.
To find the measure of ∠bac, we subtract the measure of ∠abc from 180°:
180° - 85° = 95°
Therefore, the measure of ∠bac is 95°.