Let's solve the problem based on the image you've provided. The figure shows several intersecting lines with numbered angles, and the goal is to identify:

(a) A pair of angles that form a linear pair (par lineal).
(b) A pair of vertically opposite angles (ángulos opuestos por el vértice).
(c) A pair of supplementary angles (ángulos suplementarios).

(a) Par lineal (Linear pair):

Linear pairs are adjacent angles that form a straight line, meaning their sum is $180^\circ$. In the diagram, $\angle 1$ and $\angle 2$ are adjacent and together form a straight line (along line $l$).

So, the linear pair is:
$\angle 1$ and $\angle 2$.

(b) Ángulos opuestos por el vértice (Vertically opposite angles):

Vertically opposite angles are formed when two lines intersect, and they are equal. In the diagram, $\angle 1$ and $\angle 4$ are vertically opposite.

So, the vertically opposite pair is:
$\angle 1$ and $\angle 4$.

(c) Ángulos suplementarios (Supplementary angles):

Supplementary angles add up to $180^\circ$. In this case, $\angle 5$ and $\angle 6$ are on line $m$ and together they sum to $180^\circ$.

So, the supplementary pair is:
$\angle 5$ and $\angle 6$.

Final Answers:

1. Par lineal: $\angle 1$ y $\angle 2$
2. Ángulos opuestos por el vértice: $\angle 1$ y $\angle 4$
3. Ángulos suplementarios: $\angle 5$ y $\angle 6$

Let me know if you would like further details or explanations!

Here are five related questions to extend your understanding:

1. What is the sum of a pair of supplementary angles?
2. How can you identify vertically opposite angles in any intersection?
3. Are all linear pairs supplementary? Why?
4. Can two adjacent angles be vertically opposite?
5. How many pairs of supplementary angles can you find in this diagram?

Tip: For any two lines intersecting at a point, the angles opposite each other are always equal.