besar sudut BAC ADALAH. tolong bantu kak

sudut BAC + sudut ACB = sudut DBC
(y+10) + (2y+10) = 140°
3y + 20 = 140°
3y = 140-20
3y = 120
y = 120÷3
y = 40°

sudut BAC = y+10 = 40°+10° = 50°