Question

4. In the given figure, AC is the diameter of a circle. If _CAB = 55°, then find the measure of ACB.

Answer 1

so

x+55=360

x=360-55

x=305

Answer 2

let us draw a line DC parallel to AB

therefore, angle CAB = angle ACD = 55°

DCB = ACD + ACB

90 = 55 + ACB

ACB = 90 - 55

ACB = 35°