Teaching students how to find the volume of prisms is an important topic in geometry. Finding the volume of prisms is a concept that is used in everyday life. There are many real world applications, such as determining the capacity of containers, measuring the volume of a pool, and calculating the amount of materials needed for construction. Today, we will discuss what a prism is and how to find the volume of a prism.
What are Prisms?
A prism is a three-dimensional shape that has two parallel, congruent bases and a set of rectangular sides that connect the bases. The most common types of prisms are triangular prisms, rectangular prisms, and square prisms. When we find the volume of prisms we are measuring of the amount of space that the prism occupies. See the image below for examples of prisms.
How to Find the Volume of a Prism
Step One
The first step in finding the volume of a prism is to identify the shape of the base. The base will be the 2 congruent parallel shapes that are connected by a set of rectangular sides. In a rectangular prism you can use any set of parallel bases because all of the faces/bases are rectangles. In a square prism all of the faces are congruent so any of the faces can be used as the base. See the picture below for examples of bases.
Step Two
Now that you have identified the shape of the base you can find the area of the base. Use your formulas for two-dimensional figures. The most common formulas are:
Rectangle: A = bh or A = lw
Triangle: A = 1/2bh
Square: A = b^2 or bh
The area of the base is represented by a capital B.
Step Three
Find the height of the prism. The height of a prism is the distance between the two bases. See the picture below that shows the height of prisms.
Step Four
The last step is to multiply the area of the base (step 2) and the height of the prism (step 3). Now you have the volume of prism. The formula for finding the volume is:
V = Bh where B is the area of the base and h is the height of the prism.
Remember volume is measured in units cubed. When you write the volume of an object you need to put your units.
Conclusion
The volume of a prism is an important concept in geometry and is used in many real-world applications. We hope that this post has helped you to understand the formula for finding the volume of a prism. Finding the volume of figures is used in many fields such as construction, engineering, and physics.
Want to save time planning your lessons?
Try one of our No-Prep Math Units!
Try this ready-made Volume and Surface Area of Prisms and Pyramids unit!
Each of the 8 lessons has an editable PowerPoint, guided notes, activity and practice sheet. The PowerPoints, guided notes, activities, and practice sheets also have a version in Google Slides to be used for digital learning. This unit is a TIME SAVER! You and your students will love it!
You can also check out our 6th grade Volume unit if you need something that is not as advanced. Click below for more information!
Want a FREE Digital activity on Identifying Three Dimensional Figures? Click the image below!
