Answer:Angle 3 and angle 4 are linear pairStep-by-step explanation:* Lets revise the types of angles- If two line intersected at a point, there are two types of pairs of angles- Two vertically opposite angles equal in measure- Linear pair of angles their sum is 180°* Now lets solve the problem- There are two lines intersect each other at a point- They formed between them 4 angles- Angle 2 and angle 4 are vertical opposite angles, equal in measure- Angle 1 and angle 3 are vertical opposite angles, equal in measure∴ m∠2 = m∠4∴ m∠1 = m∠3- Angle 1 and angle 2 formed a line∴ They are linear pair of angles- Angle 3 and angle 4 formed a line ∴ They are linear pair, of angles∵ m∠1 + m∠2 = 180°∴ m∠3 + m∠4 = 180°* Angle 3 and angle 4 are linear pair