tolong bantu please....

ADB = 20°
BOC = 70°

AOB = 2 × ADB = 2 × 20° = 40°

AOC = AOB + BOC = 40° + 70° = 110°
ACO = (180° - 110°)/2 = 35°
COD = 180° - AOC = 70°

BOD = 180° - AOB = 180° - 40° = 140°
DBO = (180° - BOD)/2 = 20°

CED = 1/2 × COD = 35°