Formula for Volume of a Cuboid
Learning text on the topic Formula for Volume of a Cuboid
Understanding the Volume of a Cuboid
In our daily lives, we often come across objects shaped like cuboids (or rectangular prisms) - think of boxes, bricks or even parts of buildings. A prism is defined as a 3D shape with a constant cross section. A rectangular prism is a 3D shape with six faces, each one a rectangle. When we talk about the volume of a rectangular prism using cubic units, we find out how much space it takes up. It's like figuring out how much water can fill a fish tank or how many books you can pack into a box. This volume helps us understand the capacity of these objects in cubic units, which measure space in three dimensions.
Volume Formula: The volume of a rectangular prism is calculated by multiplying its length ($l$), width ($w$) and height ($h$). The formula is $V = l \times w \times h$.
Formula for Volume of a Rectangular Prism
In maths, we often have more than one way to solve a problem, and that's true for finding the volume of a rectangular prism too.
The formula $V = l \times w \times h$ directly multiplies the prism's dimensions. This method is straightforward and effective for calculating volume.
Let’s learn how to find the volume of a cuboid with this formula.
A cuboid has a length of $4$ cm, width of $3$ cm and height of $6$ cm. Calculate its volume.
- Length ($l$) = $4$ cm
- Width ($w$) = $3$ cm
- Height ($h$) = $6$ cm
- Volume = $l \times w \times h = 4 \times 3 \times 6 = 72$ cm$^3$
The volume of this cuboid is $72$ cubic centimetres.
We use cubic units for units of volume because volume measures three-dimensional space. Think of stacking little blocks inside a box - you're filling it lengthwise, widthwise and heightwise. So, we multiply these three dimensions, and the result is in cubic units, like filling a box with tiny cubes.
Find the volume of a cuboid with a length of 5 m, a width of 2 m and a height of 3 m.
- Length ($l$) = $5$ m
- Width ($w$) = $2$ m
- Height ($h$) = $3$ m
- Volume = $l \times w \times h = 5 \times 2 \times 3 = 30$ m$^3$
The volume of this cuboid is $30$ cubic metres.
Use the formula for the volume of a cuboid, and solve these examples on your own!
Finding the Volume of a Prism with $V=Bh$
Another formula to find the volume of a rectangular prism, or cuboid, is using $V = B \times h$. Here, $B$ represents the area of the base of the shape. For a rectangular prism, this base is the area of the rectangle at the bottom. This formula is really helpful, not just for rectangular prisms, but also for other 3D shapes like cylinders which have a circular base (volume of a cylinder). It helps us understand how much space these shapes occupy by considering their base area and height.
Let's calculate the volume of a cuboid with a length of 4 feet, a width of 3 feet and a height of 6 feet.
Determine the dimensions of the cuboid:
- Length ($l$) = $4$ ft
- Width ($w$) = $3$ ft
- Height ($h$) = $6$ ft
Calculate the base area (B):
- The base area is found by multiplying the length and width.
- Base Area ($B$) = $l \times w = 4 \times 3 = 12$ square feet.
Calculate the volume using $V = B \times h$:
- Now, multiply the base area by the height.
- Volume ($V$) = $B \times h = 12 \times 6 = 72$ cubic feet.
The volume of this cuboid is $72$ cubic feet.
Practise using this formula on your own!
Formula for Volume of a Cuboid – Application
Solving problems involving the volume of a cuboid, or rectangular prism, enhances our understanding of space and capacity. It applies in diverse fields, from architecture and construction to everyday tasks like packing or storage.
Formula for Volume of a Cuboid – Summary
Key Learnings from this Text:
- Understanding the volume of a cuboid helps in calculating space in practical situations.
- The volume formula, $V = l \times w \times h$, is straightforward and widely applicable.
- Alternative method: $V = B \times h$, where $B$ is the base area, deepens conceptual understanding.
- Real-world application of this knowledge spans from storage organisation to construction planning.
Formula | Explanation |
---|---|
$V = l \times w \times h$ | Multiply length ($l$), width ($w$) and height ($h$) to find the volume. |
$V = B \times h$ | Calculate the base area ($B$ = length x width), then multiply by height ($h$). |