In the diagram above, PQ//RS. The size of the angle marked x is?
Attached Figure / Diagram
A
100o
B
80o
C
50o
D
30o
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Exterior angle = sum of two interior opposite angles
y = 50^\circ (vert. opp ∠s are equal)
X = y + 30
X = 50 + 30
X = 80^\circ
Source: Myschool Past Questions Archive (Record #9278)