Answer:
angle AOD = 90⁰
BOD = 3x⁰
90⁰+3x⁰ = 180⁰( being straight angle)
3x = 180⁰-90⁰
3x = 90⁰
x = 90⁰/3
x = 30⁰
now
y⁰+139⁰ = 180⁰(being straight angle)
y⁰ = 180⁰-139⁰
y⁰ = 41⁰
