Answer:
Explanation:
Remark
A cyclic quadrilateral have 4 angles that touch the circumference of the circle that contain the 4 angles.
A cyclic quadrilateral has 2 pairs of angles; each pair contrains 2 angles that are supplementary. This is the property that you need.
Given
y and 4y are supplementry. They are opposite one another.
Solution
y + 4y = 180 combine
5y = 180 Divide both sides by 5
5y/5 = 180/5
y = 36
Answer: y = 36