Year : 
1992
Title : 
Mathematics (Core)
Exam : 
WASSCE/WAEC MAY/JUNE

Paper 1 | Objectives

21 - 30 of 48 Questions

# Question Ans
21.

In the diagram above, TR = TS and ∠TRS = 60o. Find the value of x

A. 30

B. 45

C. 60

D. 120

E. 150

Detailed Solution

∠TRS = ∠RST = 60o
∠PSR + ∠PQR = 180o, 120o + xo = 180o
x = 60o
22.

In the diagram above, O is the center of the circle PQRS and ∠QPS = 36°. Find ∠QOS

A. 36o

B. 72o

C. 108o

D. 144o

E. 288o

Detailed Solution

< QOS = 2 < QPS (angle subtended at the centre)
\(\therefore\) < QOS = 2 x 36° = 72°
23.

In the diagram above, O is the center of the circle QOR is a diameter and ∠PSR is 37°. Find ∠PRQ

A. 37o

B. 53o

C. 65o

D. 127o

E. 147o

Detailed Solution

Construction: Join PQ.
Then < RSP = 37° = < RQP (angles on the same segment)
But < RPQ = 90° (angle in a semi-circle)
\(\therefore\) < PRQ = 180° - (90° + 37°)
= 53°
24.

In the diagram above, ML//PQ and NP//QR, if ∠LMN = 40° and ∠MNP = 55°. Find ∠QPR

A. 15o

B. 25o

C. 35o

D. 40o

E. 55o

Detailed Solution


Draw line ANB// ML
< MNA = 40° (alternate angle AB/ ML)
< ANP = 55° - 40° = 15°
< POR = 15° = < ANP (corresponding angles, PN // RQ)
25.

The angles marked in the diagram above are measured in degrees. Find x

A. 15o

B. 24o

C. 30o

D. 36o

E. 48o

Detailed Solution

Sum of exterior angles = 360°
2x + 3x + 2x + 3x + 5x = 360°
15x = 360°
x = 360°/15 = 24°
26.

Find the value of t in the diagram above

A. 5.6cm

B. 6.5cm

C. 6.6cm

D. 6.8cm

E. 7.0cm

Detailed Solution

t/4 + t
=
7/7 + 5
t = 5.6

27.

A regular polygon has each of its exterior angles as 18o. How many sides has the polygon

A. 10

B. 11

C. 12

D. 20

E. 24

Detailed Solution

360/18 = 20
28.

In the diagram above, PQT is an isosceles triangle.|PQ| = |QT|, ∠SRQ = 75°, ∠QPT = 25° and PQR is straight line. Find ∠RST

A. 20o

B. 50o

C. 55o

D. 70o

E. 75o

Detailed Solution

< PTQ = 25° (base angles of an isos. triangle)
\(\therefore\) < PQT = 180° - (25° + 25°) = 130° (sum of angles in triangle PQT)
\(\therefore\) < RST = 130° - 75° = 55° (exterior angle = sum of 2 opp. interior angles)
29.

Sin 60° has the same value as I. Sin 120° II. cos 240° III. -sin 150° IV. cos 210° V. sin 240°

A. I only

B. II only

C. IV only

D. III only

E. IV and V only

Detailed Solution

In the second quadrant, \(\sin 120 = \sin (180 - 120)\)
= \(\sin 60\)
30.

If cos θ = 5/13, what is the value of tan \(\theta\) for 0 < θ < 90° ?

A. 13

B. 5

C. 13/5

D. 12/5

E. 5/12

Detailed Solution

\(\cos \theta = \frac{5}{13}\)
\(\implies\) In the right- angled triangle, with an angle \(\theta\), the adjacent side to \(\theta\) = 5 and the hypotenuse = 13.
\(\therefore 13^2 = opp^2 + 5^2\)
\(opp^2 = 169 - 25 = 144 \implies opp = \sqrt{144}\)
= 12.
\(\tan \theta = \frac{opp}{adj} = \frac{12}{5}\)
21.

In the diagram above, TR = TS and ∠TRS = 60o. Find the value of x

A. 30

B. 45

C. 60

D. 120

E. 150

Detailed Solution

∠TRS = ∠RST = 60o
∠PSR + ∠PQR = 180o, 120o + xo = 180o
x = 60o
22.

In the diagram above, O is the center of the circle PQRS and ∠QPS = 36°. Find ∠QOS

A. 36o

B. 72o

C. 108o

D. 144o

E. 288o

Detailed Solution

< QOS = 2 < QPS (angle subtended at the centre)
\(\therefore\) < QOS = 2 x 36° = 72°
23.

In the diagram above, O is the center of the circle QOR is a diameter and ∠PSR is 37°. Find ∠PRQ

A. 37o

B. 53o

C. 65o

D. 127o

E. 147o

Detailed Solution

Construction: Join PQ.
Then < RSP = 37° = < RQP (angles on the same segment)
But < RPQ = 90° (angle in a semi-circle)
\(\therefore\) < PRQ = 180° - (90° + 37°)
= 53°
24.

In the diagram above, ML//PQ and NP//QR, if ∠LMN = 40° and ∠MNP = 55°. Find ∠QPR

A. 15o

B. 25o

C. 35o

D. 40o

E. 55o

Detailed Solution


Draw line ANB// ML
< MNA = 40° (alternate angle AB/ ML)
< ANP = 55° - 40° = 15°
< POR = 15° = < ANP (corresponding angles, PN // RQ)
25.

The angles marked in the diagram above are measured in degrees. Find x

A. 15o

B. 24o

C. 30o

D. 36o

E. 48o

Detailed Solution

Sum of exterior angles = 360°
2x + 3x + 2x + 3x + 5x = 360°
15x = 360°
x = 360°/15 = 24°
26.

Find the value of t in the diagram above

A. 5.6cm

B. 6.5cm

C. 6.6cm

D. 6.8cm

E. 7.0cm

Detailed Solution

t/4 + t
=
7/7 + 5
t = 5.6

27.

A regular polygon has each of its exterior angles as 18o. How many sides has the polygon

A. 10

B. 11

C. 12

D. 20

E. 24

Detailed Solution

360/18 = 20
28.

In the diagram above, PQT is an isosceles triangle.|PQ| = |QT|, ∠SRQ = 75°, ∠QPT = 25° and PQR is straight line. Find ∠RST

A. 20o

B. 50o

C. 55o

D. 70o

E. 75o

Detailed Solution

< PTQ = 25° (base angles of an isos. triangle)
\(\therefore\) < PQT = 180° - (25° + 25°) = 130° (sum of angles in triangle PQT)
\(\therefore\) < RST = 130° - 75° = 55° (exterior angle = sum of 2 opp. interior angles)
29.

Sin 60° has the same value as I. Sin 120° II. cos 240° III. -sin 150° IV. cos 210° V. sin 240°

A. I only

B. II only

C. IV only

D. III only

E. IV and V only

Detailed Solution

In the second quadrant, \(\sin 120 = \sin (180 - 120)\)
= \(\sin 60\)
30.

If cos θ = 5/13, what is the value of tan \(\theta\) for 0 < θ < 90° ?

A. 13

B. 5

C. 13/5

D. 12/5

E. 5/12

Detailed Solution

\(\cos \theta = \frac{5}{13}\)
\(\implies\) In the right- angled triangle, with an angle \(\theta\), the adjacent side to \(\theta\) = 5 and the hypotenuse = 13.
\(\therefore 13^2 = opp^2 + 5^2\)
\(opp^2 = 169 - 25 = 144 \implies opp = \sqrt{144}\)
= 12.
\(\tan \theta = \frac{opp}{adj} = \frac{12}{5}\)