In the diagram, ST//PQ reflex angle SRQ = 198o and o. Find the value of y
-
A.
18o -
B.
54o -
C.
87o -
D.
92o
Correct Answer: Option B
Explanation
R +198 = 360(angles at a point)
R = 360 – 198 = 162o
C = 72(alternate angle), b + c = 180(angles or straight line)
b = 190 – c = 180 – 72 = 108
a + b = R = 162
a = R – b = 162 – 108
= 54, but a = y(alternate angles)
y = 54o