Volume of a cone with radius r and height h is:
A(2/3) π r² h
Bπ r² h
C(1/3) π r² h
Dπ r h
Answer & Solution
Correct answer: C. (1/3) π r² h
To find the volume of a cone, we compare it to a cylinder with the same radius $r$ and height $h$.
1. **Base Area**: The base of a cone is a circle. The area of this base is given by the formula:
$$A = \pi r^2$$
2. **Relationship to a Cylinder**: A cylinder with the same dimensions has a volume of $V_{cylinder} = \text{Base Area} \times \text{Height} = \pi r^2 h$.
3. **The Cone Factor**: In geometry, it is proven (through calculus or physical displacement experiments) that a cone occupies exactly one-third of the volume of a cylinder with the same base and height.
4. **Final Formula**: Multiplying the cylinder volume by $1/3$, we get:
$$V = \frac{1}{3} \pi r^2 h$$
Therefore, the correct option is **(1/3) π r² h**.
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