In the figure, PQRS is a circle. If chords QR and RS are equal, calculate the value of x
Attached Figure / Diagram
A
80o
B
60o
C
45o
D
40o
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
SRT is a straight line, where QRT = 120
SRQ = 180o - 120o = 60o - (angle on a straight line)
also angle QRS = 180o - 100o (angle on a straight line) . In angles where QR = SR and angle SRQ = 60o
x = 100 - 60 = 40o
Source: Myschool Past Questions Archive (Record #32837)