Question 1:
Conclusion: ∠DAY + ∠YAK = 180°
Justification: definition of linear pair
Question 2:
Conclusion: Point U is the midpoint of RN
Justification: RU=UN, definition of midpoint
Question 4:
Conclusion: ∠3 = ∠7
Justification: definition of alternate interior angles
Question 5:
Conclusion: ∠ABD = ∠DBC
Justification: definition of bisector
Question 6:
Conclusion: ∠2 and ∠3 are supplementary angles
Justification: definition of supplementary angles
Sorry question 3, don't know what it's trying to say