A) $36^\circ$
B) $72^\circ$
C) $108^\circ$
D) $144^\circ$

Solution Hint: Perimeter = Arc length + $2r$. Find arc length, then use $L = \frac{\theta}{360}2\pi r$. (Answer: B)

Question 11: An arc of a circle subtends an angle of $60^\circ$ at the centre. If the radius is 3 cm, calculate the length of the arc. (Take $\pi = \frac{22}{7}$)

A) $\frac{11}{7} \text{ cm}$
B) $\frac{22}{7} \text{ cm}$
C) $\frac{33}{7} \text{ cm}$
D) $\frac{44}{7} \text{ cm}$

Solution Hint: Use $L = \frac{\theta}{360}2\pi r$. (Answer: B)

2. JAMB Questions on Three-Dimensional Shapes

2.1 Cuboids and Cubes

Question 12: A rectangular tank has dimensions 10 m by 8 m by 5 m. What is its volume?
- A) $23 \text{ m}^3$
- B) $400 \text{ m}^3$
- C) $130 \text{ m}^3$
- D) $80 \text{ m}^3$
Solution Hint: Use $V = lbh$. (Answer: B)
Question 13: The total surface area of a cube is $294 \text{ cm}^2$. Find the length of one side of the cube.
- A) 6 cm
- B) 7 cm
- C) 8 cm
- D) 9 cm
Solution Hint: Use $A = 6s^2$ and solve for $s$. (Answer: B)

2.2 Cylinders

Question 14: A cylindrical can has a radius of 3 cm and a height of 10 cm. Calculate its volume. (Take $\pi = 3.142$)
- A) $94.26 \text{ cm}^3$
- B) $188.52 \text{ cm}^3$
- C) $282.78 \text{ cm}^3$
- D) $314.2 \text{ cm}^3$
Solution Hint: Use $V = \pi r^2 h$. (Answer: C)
Question 15: The curved surface area of a cylinder is $176 \text{ cm}^2$. If its radius is 7 cm, find its height. (Take $\pi = \frac{22}{7}$)
- A) 2 cm
- B) 3 cm
- C) 4 cm
- D) 5 cm
Solution Hint: Use CSA $= 2\pi rh$ and solve for $h$. (Answer: C)

2.3 Cones

Question 16: A cone has a base radius of 7 cm and a height of 24 cm. Calculate its volume. (Take $\pi = \frac{22}{7}$)
- A) $1232 \text{ cm}^3$
- B) $1642 \text{ cm}^3$
- C) $1848 \text{ cm}^3$
- D) $3696 \text{ cm}^3$
Solution Hint: Use $V = \frac{1}{3}\pi r^2 h$. (Answer: A)
Question 17: The height of a cone is 8 cm and its base radius is 6 cm. Find its slant height.
- A) 7 cm
- B) 10 cm
- C) 14 cm
- D) 100 cm
Solution Hint: Use $l = \sqrt{r^2+h^2}$. (Answer: B)
Question 18: What is the curved surface area of the cone in Question 17? (Take $\pi = 3.142$)
- A) $60\pi \text{ cm}^2$
- B) $188.52 \text{ cm}^2$
- C) $120\pi \text{ cm}^2$
- D) $376.99 \text{ cm}^2$
Solution Hint: Use CSA $= \pi rl$. (Answer: B)

2.4 Spheres

Question 19: A sphere has a radius of 6 cm. Calculate its volume. (Take $\pi = 3.142$)
- A) $452.45 \text{ cm}^3$
- B) $904.92 \text{ cm}^3$
- C) $113.10 \text{ cm}^3$
- D) $226.19 \text{ cm}^3$