When determining the 'size' of a cylinder, it most commonly refers to finding its volume, which measures the three-dimensional space it occupies. Calculating the volume of a cylinder is a straightforward process once you know its fundamental dimensions: the radius of its base and its height.
Understanding Cylinder Volume
A cylinder is a three-dimensional geometric shape with two parallel circular bases and a curved surface connecting them. To find its "size" (volume), you need two key measurements:
- Radius (r): The distance from the center of the circular base to its edge. If you have the diameter, simply divide it by two to get the radius.
- Height (h): The perpendicular distance between the two circular bases.
The Formula for Cylinder Volume
The precise method for finding the volume of a cylinder involves a specific mathematical formula. As per the reference, the formula is:
Volume = π ⋅ radius² ⋅ height
This can be more concisely written as:
V = πr²h
Where:
V
represents the Volume of the cylinder.π
(pi) is a mathematical constant approximately equal to 3.14 (as specified in the reference for calculation purposes).r
represents the radius of the cylinder's base.h
represents the height of the cylinder.
Step-by-Step Calculation of Cylinder Volume
To find the size (volume) of a cylinder, follow these straightforward steps:
-
Identify the Dimensions
Measure or identify the radius (r) of the cylinder's base and its height (h). Ensure both measurements are in the same units (e.g., centimeters, inches, meters).
-
Write the Formula
State the volume formula for a cylinder:
Volume = π ⋅ radius² ⋅ height
orV = πr²h
. -
Substitute the Dimensions into the Formula
Plug the values you identified for the radius and height into the formula. As instructed, use 3.14 as the value for $\pi$ (pi) for your calculation.
- Example: If the radius (r) is 5 cm and the height (h) is 10 cm, the substitution would look like:
V = 3.14 ⋅ (5 cm)² ⋅ 10 cm
.
- Example: If the radius (r) is 5 cm and the height (h) is 10 cm, the substitution would look like:
-
Solve the Equation
Perform the calculations according to the order of operations (PEMDAS/BODMAS):
- First, square the radius (
r²
). - Then, multiply the squared radius by the value of $\pi$ (3.14).
- Finally, multiply that result by the height (
h
).
- First, square the radius (
The final answer will be in cubic units (e.g., cm³, m³, in³), which represents the three-dimensional space the cylinder occupies.
Practical Example: Calculating Cylinder Volume
Let's find the volume of a water tank that is cylindrical in shape.
Given:
- Radius of the tank's base (r) = 2 meters
- Height of the tank (h) = 5 meters
Step No. | Action | Calculation |
---|---|---|
1. | Identify Dimensions | r = 2 m , h = 5 m |
2. | Write the Formula | V = πr²h |
3. | Substitute Values (using π = 3.14 ) |
V = 3.14 ⋅ (2 m)² ⋅ 5 m |
4. | Solve the Equation | V = 3.14 ⋅ (4 m²) ⋅ 5 m V = 3.14 ⋅ 20 m³ V = 62.8 m³ |
Therefore, the volume (or "size") of the cylindrical water tank is 62.8 cubic meters. This means the tank can hold 62.8 cubic meters of water.