Answer:
∠COA = 160°
Explanation:
The angle intercepted on opposite side of the circle from an ARC has a measure of HALF of the Arc.
∠CBA is HALF of the ARC CA
∠CBA is given as 80°
So Arc CA is 80 * 2 = 160°
Now,
∠COA is an intercepted angle that is at the CENTER. This angle has same measure as the Arc it is intercepted from (Arc CA).
Hence,
∠COA = Arc CA
∠COA = 160°