Answer:
m<A = 40°
m<C = 113°
Explanation:
Problem 1:
m<A = ½(arc BC) (Inscribed angle theorem)
Substitute
m<A = ½(80°)
m<A = 40°
Problem 2:
Given that m<A = 67°
Recall: angels that are opposite each other in any given inscribed quadrilateral are supplements of each other.
Thus, it implies that:
m<A + m<C = 180°
Substitute
67° + m<C = 180°
Subtract 67° from each side
m<C = 180° - 67°
m<C = 113°