JAMB Mathematics Past Questions & Answers - Page 120

596.

In the diagram, QPS = SPR, PR = 9cm. PQ = 4cm and QS = 3cm, find SR.

A.

6\(\frac{3}{4}\)cm

B.

3\(\frac{3}{8}\)cm

C.

4\(\frac{3}{8}\)cm

D.

2\(\frac{3}{8}\)cm

Correct answer is A

Using angle bisector theorem: line PS bisects angle QPR

QS/QP = SR/PR

3/4 = SR/9

4SR = 27

SR = \(\frac{27}{4}\)

= 6\(\frac{3}{4}\)cm

597.

In the figure, PT is tangent to the circle at U and QU/RS if TUR = 35º and SRU = 50º find x

A.

95o

B.

85o

C.

50o

D.

35o

Correct answer is A

Since QRU= Xo

RSU = Xo, But RSU = 180o - (50o + 35o)

= 180o - 85o

= 95o

x = 95o

598.

In the diagram, QP//ST:PQR = 34o qrs = 73o and Rs = RT. Find SRT

A.

68o

B.

102o

C.

107o

D.

141o

Correct answer is B

Construction joins R to P such that SRP = straight line

R = 180o - 107o

< p = 180o - (107o - 34o)

108 - 141o = 39o

Angle < S = 39o (corr. Ang.) But in \(\bigtriangleup\)SRT

< S = < T = 39o

SRT = 180 - (39o + 39o)

= 180o - 78o

= 102o

599.

In the diagram, O is the centre of the circle and POQ a diameter. If POR = 96o, find the value of ORQ.

A.

84o

B.

48o

C.

45o

D.

42o

Correct answer is B

OQ = OR = radii

< ROQ = 180 - 86 = 84o

\(\bigtriangleup\)OQR = Isosceles

R = Q

R + Q + 84 = 180(angle in a \(\bigtriangleup\))

2R = 96 since R = Q

R = 48o

ORQ = 48o

600.

In the diagram, PQRS is a circle with O as centre and PQ/RT. If RTS = 32°. Find PSQ

A.

32o

B.

45o

C.

58o

D.

90o

Correct answer is C

< PSO = \(\frac{1}{2}\) < SOQ = \(\frac{1}{2}\)(180) = 90°

< RTS = < PQS = 32° (Alternative angle)

< PSQ = 90 - < PSQ = 90° - 32°

= 58°