WAEC Mathematics Past Questions & Answers - Page 325

1,621.

The angle of a sector of a circle of diameter 8cm is 135°. Find the area of the sector [Take \(\pi\) = 22/7].

A.

\(9\frac{3}{7}cm^2\)

B.

\(12\frac{4}{7}cm^2\)

C.

\(18\frac{6}{7}cm^2\)

D.

\(25\frac{1}{7}cm^2\)

Correct answer is C

Area of a sector

\(\frac{θ}{360°} * πr^2\)

= \(\frac{135}{360} * 3.142 * 4 * 4\)

= \(18\frac{6}{7}cm^2\)

 

1,623.

Find the volume of a cone of radius 3.5cm and vertical height 12cm [Take π = 22/7]

A.

3.4cm2

B.

15.5cm2

C.

21.0cm2

D.

42.0cm2

E.

154.0cm2

Correct answer is E

No explanation has been provided for this answer.

1,624.

With reference to the graph above, which f the following solution sets is represented by ΔOPQ?

A.

y ≥ x, y ≤ 0, y + x ≥ 7

B.

y ≤ x, y ≥ 0, y + x ≤ 7

C.

y ≥ x, y ≥ 0, y + x ≤ 7

D.

y ≤ x, y ≤ 0, y + x ≤ 7

E.

y ≤ x, y ≥ 0, y + x ≥ 7

Correct answer is D

No explanation has been provided for this answer.

1,625.

In the diagram above, what is the size of angle ACB?

A.

40o

B.

50o

C.

60o

D.

80o

E.

100o

Correct answer is C

< ABC = 80° (alternate angles)

< ACB = 180° - (80° + 40°) = 60°