Surface Area of a Right Triangular Prism – Definition with Examples
Created on Dec 18, 2023
Updated on January 5, 2024
Hello there, bright minds! Welcome back to Brighterly, your companion in the thrilling journey through the wonderful world of mathematics. We continue our exploration today with a plunge into the world of geometric shapes, landing right into the realm of right triangular prisms.
Understanding complex mathematical concepts can sometimes feel like climbing a steep hill, but fear not! Here at Brighterly, we believe that learning can be an exhilarating adventure. So, put on your explorer hats, because we’re going to turn the seemingly daunting task of learning the surface area of right triangular prisms into an exciting and funfilled experience.
Let’s kickstart our expedition by understanding what a right triangular prism is, followed by grasping the concept of surface area. We’ll then delve into the intricacies of properties and surface area calculations of right triangular prisms. We’ll even embark on the adventure of deriving the formula for surface area and practice some problems to put our knowledge to the test.
What is a Right Triangular Prism?
Welcome to another exciting topic in our evergrowing series at Brighterly! Today, we’ll dive deep into the fascinating world of geometric shapes, specifically focusing on the right triangular prism.
A right triangular prism is a fascinating geometric shape. Imagine a threedimensional object where the two ends look like triangles and the sides are rectangles. You’ve just visualized a right triangular prism. The ‘right’ in the name indicates that the triangle at the ends is a right triangle, meaning it has one angle that measures exactly 90 degrees.
Definition of a Right Triangular Prism
Strictly speaking, a right triangular prism is a fivefaced polyhedron whose base and top are identical right triangles, and whose other three faces are rectangles. The shape is called a prism because the crosssection (the shape you get if you slice it parallel to the base) is always the same right triangle.
What is Surface Area?
Now let’s discuss surface area. If you’ve ever painted a room, wrapped a present, or put up a tent, you’ve already dealt with the concept of surface area, even if you didn’t realize it at the time.
Definition of Surface Area
In mathematical terms, the surface area is the total area that the surface of an object occupies. It is measured in square units and is the sum of all the areas of all shapes that cover the surface of the object.
Properties of a Right Triangular Prism
When it comes to a right triangular prism, there are a few unique properties. The base and top faces are congruent right triangles, meaning they have the same size and shape. The other three faces, which are rectangles, connect these triangles. When you put these faces together, you form the prism’s surface.
Properties of Surface Area
The surface area of a geometric shape is simply the sum of the areas of all its faces. For a right triangular prism, this includes the areas of the two triangular ends and the three rectangular sides.
How to calculate the Surface Area of a Right Triangular Prism?
Calculating the surface area of a right triangular prism isn’t as daunting as it might first appear. The key is to break it down into smaller, manageable parts – the triangles and the rectangles – and then add those areas together.
Difference Between Surface Area and Volume of a Right Triangular Prism
Surface area and volume are two vital concepts in geometry, but they serve different purposes. While surface area measures the total area that the surface of an object occupies, volume is a measure of the space that the object occupies or can contain, typically measured in cubic units.
Formulas for Surface Area of a Right Triangular Prism
The formula to calculate the surface area of a right triangular prism is quite straightforward: Surface Area = (Perimeter of the base * Height) + 2 * (Area of the base triangle)
Deriving the Formula for Surface Area of a Right Triangular Prism
The formula for the surface area of a right triangular prism isn’t plucked out of thin air; it is derived logically from the properties of the shape. As mentioned, a right triangular prism has five faces: two triangular faces and three rectangular ones.
First, let’s focus on the three rectangular faces. Each rectangle’s area is calculated by multiplying its length (the same as the hypotenuse of the triangular base) by its width (which is the height of the prism). As there are three identical rectangular faces, we can calculate the combined area as the perimeter of the base times the height (Ph).
The two triangular faces are congruent, meaning they have the same dimensions. The area of a triangle is calculated by multiplying the base by the height and then dividing by 2. Since we have two such triangles, we double this value (2 * (0.5 * base * height)).
Adding these two components together, we get our formula: Surface Area = Ph + 2 * (0.5 * base * height), which simplifies to Surface Area = Ph + base * height.
Writing Surface Area Formulas for Different Right Triangular Prisms
Given the variety of right triangular prisms, the specific dimensions can vary, affecting the specific formula for surface area. However, regardless of dimensions, the formula’s essence remains the same.
For example, consider a right triangular prism with a base of 4 units, a height of 3 units for the triangle, and a prism height of 6 units. The hypotenuse (the longest side of the triangle) would be 5 units, considering the Pythagorean theorem. So, the surface area would be:
SA = Perimeter * height + 2 * Area of base triangle = (4+3+5) * 6 + 2 * (0.5 * 4 * 3) = 72 + 12 = 84 square units.
This formula applies regardless of the size of the right triangular prism, you just need to replace the values with your specific measurements.
Practice Problems on Surface Area of Right Triangular Prisms
To fully grasp the concept of calculating the surface area of right triangular prisms, practice is vital. Here are some practice problems:

Problem 1: A right triangular prism has a base of 7 units, a height of 24 units, and the hypotenuse of the base triangle is 25 units. Find its surface area.

Problem 2: A right triangular prism has equal sides of length 10 units. What is its surface area?

Problem 3: If the base triangle of a right triangular prism has sides of lengths 5, 12, and 13 units, and the prism’s height is 15 units, calculate the surface area.
Remember, you can always use the surface area formula, replace the values with your specific measurements, calculate the areas of the rectangular and triangular faces separately, and then add them up to get the total surface area. Happy calculating!
Conclusion
As we conclude our mathematical exploration today at Brighterly, we hope that you now feel confident and ready to tackle any problem related to the surface area of a right triangular prism that comes your way. The exciting world of geometry is full of such intriguing shapes and concepts waiting to be discovered.
Always remember, mathematics is not just about numbers; it is about understanding the underlying patterns and principles that govern our world. And with Brighterly, you are not alone on this journey. We’re here to make every complex concept understandable, every tough problem solvable, and every learning moment enjoyable.
Stay curious, stay eager, and continue your journey into the amazing world of mathematics. The more you explore, the brighter you shine. That’s the Brighterly way!
Frequently Asked Questions on Surface Area of Right Triangular Prisms
Why do we need to calculate the surface area of a right triangular prism?
The surface area of a shape tells us how much material is needed to cover the shape completely. In practical terms, this could be useful in many reallife scenarios, like painting a wall, packaging a box, or building a tent.
How does the size of the base triangle affect the surface area?
The size of the base triangle has a direct impact on the surface area. The larger the base triangle, the greater the surface area, because the base triangle determines the size of the three rectangular faces and one of the triangular faces.
What’s the difference between surface area and volume in a right triangular prism?
Surface area refers to the total area that the surface of an object occupies. It is measured in square units. Volume, on the other hand, is a measure of the space that an object occupies or can contain. It is measured in cubic units. For a right triangular prism, you’d use the surface area to determine how much material is needed to cover the shape, while volume would tell you how much the shape can hold.
Why is it called a ‘right’ triangular prism?
It’s called a ‘right’ triangular prism because the triangle forming the base and top faces of the prism is a right triangle, which means one of its angles is a right angle (90 degrees).
Remember, at Brighterly, we are always here to help you illuminate the path of mathematical discovery. Happy exploring!