Final answer:
After setting up a system of equations based on the relationship between the two angles, it is found that the smaller angle is 40° and its supplement is 140°. However, this correct pair of angles does not match any of the answer choices provided in the question.
Step-by-step explanation:
The question asks us to find two angles where one angle is the supplement of the other and the measure of the supplement is 20 degrees less than 4 times the measure of the smaller angle. We declare two variables: let angle A be the measure of the smaller angle, and angle B be the measure of its supplement. According to the properties of supplementary angles, A + B = 180° (since supplementary angles add up to 180 degrees).
According to the problem statement, we also have that B = 4A - 20°. We can now set up a system of equations and solve for A:
- A + B = 180°
- B = 4A - 20°
We substitute the second equation into the first:
- A + (4A - 20°) = 180°
- 5A - 20° = 180°
- 5A = 200°
- A = 40°
Now that we have the measure of angle A, we can find the measure of B by plugging A back into the second equation:
- B = 4(40°) - 20°
- B = 160° - 20°
- B = 140°
Therefore, the two angles are A = 40° and B = 140°. This was not one of the answer choices provided, indicating there may have been an error in the question or the provided choices.