Q1: Define vertically opposite angles. Are they always equal?
Ans: Vertically opposite angles are the angles opposite each other when two lines intersect. Yes, they are always equal.
Q2: Two angles form a linear pair. If one is 125°, find the other.
Ans: The other angle = 180° − 125° = 55°
Q3: Name a pair of lines that never intersect.
Ans: Parallel lines
Q4: A transversal cuts two lines and ∠1 = ∠5. What kind of angles are these, and what can you conclude about the lines?
Ans: Corresponding angles; the lines are parallel.
Q5: If ∠x and ∠y are supplementary and ∠x = 2∠y, find the angles.
Ans: ∠y = 60°, ∠x = 120°
Q6: ∠3 and ∠6 are equal and lie between two lines on opposite sides of the transversal. What type are they?
Ans: Alternate interior angles
Q7: Which angles lie between the two lines and on the same side of a transversal?
Ans: Co-interior (or consecutive interior) angles
Q8: How many pairs of corresponding angles are formed when a transversal cuts two lines?
Ans: 4 pairs