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Showing 1 question in Mathematics for Class 10. Tap a card to reveal the answer.
MathematicsSurface Areas and VolumeseasyFind the volume of a cone whose base radius is 3 cm and height is 4 cm. (Take pi = 22/7.)
Reveal answer ↓
What it is
A cone's volume is exactly one-third of a cylinder with the same base and height.
Answer
Volume of a cone = (1/3) x pi x r^2 x h = (1/3) x (22/7) x 3^2 x 4 = (1/3) x (22/7) x 36 = (22 x 12) / 7 = 264/7, which is about 37.7 cubic cm.
V(cone) = (1/3) pi r^2 h
- •V = (1/3) pi r^2 h
- •= (1/3)(22/7)(9)(4)
- •= 264/7 = about 37.7 cm^3
Why learn this
It's how we measure ice-cream cones, funnels, heaps of grain and tent capacity.
💡 Memory trick
Cone = 1/3 x pi r^2 h - a cone is a third of its cylinder.