In the given figure, l || m and p || q. Find the angles x, y and z.

Consider p || q and l is a transversal:

x° = 100° $\quad$[Alternate angles]

Consider l || m:

z° = 100° $\quad$[Corresponding angles]

Let the angle vertically opposite to y° be t°.

Now, t° and z° are co-interior:

∴ t° + z° = 180°

⇒ t° + 100° = 180°

⇒ t° = 180° - 100°

⇒ t° = 80°

y° = t° $\quad$[Vertically opposite angles]

∴ y° = 80°

x° = 100°, y° = 80° and z° = 100°