Given that one of the angle is 80°
∠z and 80° are vertically opposite angles
Therefore ∠z = 80°
∠z and ∠t are corresponding angles
∠z = ∠t
Therefore, ∠t = 80°
∠z and ∠y are corresponding angles
∠z = ∠y
Therefore, ∠y = 80°
∠x and ∠y are corresponding angles
∠y = ∠x
Therefore, ∠x = 80°