Answer:
m<c = 104°
m<d = 80°
Step-by-step explanation:
Recall: Opposite angles of a cyclic quadrilateral are supplementary. Therefore, their sum equals 180°. Thus:
m<c + 76° = 180°
m<c + 76° - 76° = 180° - 76° (subtraction property of equality)
m<c = 104°
m<d + 100° = 180°
m<d +100° - 100° = 180° - 100° (subtraction property of equality)
m<d = 80°
