JAMB - Mathematics (1988 - No. 43)
In the figure, PQRS is a circle. If chords QR and RS are equal, calculate the value of x
80o
60o
45o
40o
説明
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
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