In the given figure, AB || CD || EF. Find x, y and z.

Consider AB || CD and AD is a transversal:

x° = 140° $\quad$[Alternate angles]

Since, x°, y° and 120° meet at same point D and form a complete angle:

x° + y° + 120° = 360°

⇒ 140° + y° + 120° = 360° $\quad$[Substituting the value of x]

⇒ 260° + y° = 360°

⇒ y° = 360° - 260°

⇒ y° = 100°

y° and z° are co-interior angles.

Co-interior angles are supplementary:

∴ y° + z° = 180°

⇒ 100° + z° = 180° $\quad$[Substituting the value of y]

⇒ z° = 180° - 100°

⇒ z° = 80°

x° = 140°, y° = 100° and z° = 80°