The radius of a solid cylinder is 12 cm, and its height is 25 cm. A three-dimensional sector with a sector angle of 45o is removed from it, all along the height of the cylinder. What is the volume (in cm3) of the larger piece of the cylinder?
- AOption (a)
3200
- BOption (b)
3250
- COption (c)
3150
- DOption (d)
3000
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Correct answer
3150
Why this answer is correct

Shortcut Trick
Removed part = 45° out of 360° ⇒ removed = 1/8
Remaining volume = 7/8 of cylinder
Total volume = πr2h = π × 122 × 25 = 3600π
Required = 7/8 × 3600π = 3150π
∴ Answer = 3150π

Alternate Method
45° r = 12 cm
Given:
r = 12 cm, h = 25 cm, angle = 45°
Formula:
Volume of cylinder = πr2h
Sector volume = (θ/360) × πr2h
Calculations:
⇒ Total volume = π × 122 × 25 = 3600π
⇒ Removed volume = (45/360) × 3600π = 1/8 × 3600π = 450π
⇒ Remaining = 3600π − 450π = 3150π
Final Answer: 3150π cm3

Additional Information
Volume of Cylinder: πr2h → depends on base area and height.
Sector of Cylinder: Fraction = θ/360 → same fraction applies to volume.
Mensuration Shortcut: Always find fraction removed first to save time.
Angle Conversion: 45° = 1/8 of full circle (360°).









































