Answer:
Angle O is 72 degrees. Angle C is 18 degrees.
Explanation:
You know that angle B is 90 degrees because Lines AC and OB are perperdicular at point B.
Add together all of the angles in the triangle
a + 4a + 90 = 180 Combine like terms
5a + 90 = 180
- 90 - 90 Subtract 90 from both sides
5a = 90 Divide both sides by 5
a = 18
Plug this answer into the angles to find their measures
Angle C = 18 degrees
Angle O = 4(18) = 72 degrees