Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

Let's learn what a truncated pyramid is, how to calculate the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid in the article below.

Table of Contents

Definition of frustum

A truncated pyramid is a part of a polyhedron, located between the base and the cross-section cut by a plane parallel to the base of the pyramid.

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

  • The figure consisting of polygons A1A2...An,B1B2...BnA1A2...An,B1B2...Bn and trapezoids A1A2B2B1,A2A3B3B2,...,AnA1B1BnA1A2B2B1,A2A3B3B2,...,AnA1B1Bn is called a truncated pyramid, denoted as A1A2...An.B1B2...Bn.A1A2...An.B1B2...Bn.
  • Simply put, a truncated pyramid is formed from the pyramid S.A1A2...AnS.A1A2...An after cutting off the pyramid S.B1B2...Bn.S.B1B2...Bn.

+ The polygons A1A2...An,B1B2...BnA1A2...An,B1B2...Bn are called the two bases,

+ Trapezoids A1A2B2B1,A2A3B3B2,...,AnA1B1BnA1A2B2B1,A2A3B3B2,...,AnA1B1Bn are called lateral faces.

+ The line segments A1B1,A2B2,...,AnBnA1B1,A2B2,...,AnBn are called the side edges, the edges of the base surface are called the base edges.

+ The distance between the two bases is called the height of the truncated pyramid.

Properties of truncated pyramid:

  • The two bases are two polygons (triangles, quadrilaterals, pentagons, etc.) with corresponding parallel sides and equal ratios of corresponding sides.
  • The side faces are all trapezoids.
  • The lines containing the lateral edges will converge at a point (the top of the pyramid).
  • A truncated pyramid is a pyramid whose bases are regular polygons (with equal sides). Therefore, the lateral faces of a truncated pyramid are all equal isosceles trapezoids.

Formula for calculating the area of ​​a truncated pyramid

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

Surface area of ​​truncated pyramid

The lateral area of ​​a truncated pyramid is the area of ​​the surrounding faces, the part surrounding the truncated pyramid, excluding the area of ​​the two bases.

How to calculate the lateral area of ​​a truncated pyramid: Calculate the area of ​​each side face (trapezoids) of the truncated pyramid according to the formula for calculating the area of ​​a normal trapezoid , then calculate the total area.

Formula for calculating the area of ​​a regular truncated pyramid:

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

In there:

  • Sxq: surrounding area
  • n: number of lateral faces of the truncated pyramid (equal to the number of edges of the base polygon)
  • a, b: side lengths of the upper and lower bases respectively
  • h: height of the side quadrilaterals.

Example 1: 

Calculate the lateral area of ​​a regular quadrilateral truncated pyramid with base edges of 10cm and 15cm and side height of 12cm.

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

Prize: 

The side face of a regular quadrilateral truncated pyramid is an isosceles trapezoid, so the area of ​​one side face is:

A regular quadrilateral truncated pyramid has 4 equal sides, so its lateral area is:

150 x 4 = 600 (cm2)

Example 2: Calculate the lateral area of ​​a regular quadrilateral truncated pyramid with base edges of 6cm and 8cm and side height of 5cm. Calculate the lateral area of ​​a regular quadrilateral truncated pyramid with base edges of 6cm and 8cm.

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

Prize: 

The side face of a regular quadrilateral truncated pyramid is an isosceles trapezoid, so the area of ​​one side face is equal to

A regular quadrilateral truncated pyramid has four equal sides so its lateral area is equal to

35 x 4 = 140 (cm2)

Total surface area of ​​a truncated pyramid

The total area of ​​a truncated pyramid is equal to the sum of the lateral area and the area of ​​the two bases.

Formula:                    Stp = Sxq + Big bottom + Small bottom

In there:

  • Stp: Total area
  • Sxq: Surrounding area
  • Large base: Large base area
  • Small base: Small base area

For example: 

Calculate the total area of ​​a regular truncated pyramid according to the dimensions given in the figure.

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

Prize:

We have:

AD = 12 ⇒ OJ = 6

Draw II1 ⊥ OJ we have: I1J = 3

Applying the Pythagorean theorem to right triangle II1J we have:

IJ2 = II12 + I1J2 = 92 + 32 = 90

Hence:

The area of ​​one side of a trapezoid is:

The surrounding area is equal to:

The area of ​​the upper base is: S = 6 x 6 = 36 (units)

The area of ​​the bottom base is: S = 12 x 12 = 144 (units)

The total area of ​​a truncated pyramid is equal to:

Formula for calculating the volume of a truncated pyramid

Recipe:

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

In there:

  • V: volume of truncated pyramid
  • S, S' are the areas of the large and small bases of the pyramid, respectively.
  • h: height of the pyramid, that is the distance between the two large and small bases

Is a truncated pyramid a square (regular quadrilateral):

Formula for calculating the volume of a truncated pyramid, the lateral area and total area of ​​a truncated pyramid

In there:

  • V: Volume
  • h: Height of the pyramid
  • a, b are the lengths of the edges of the large base and the small base respectively.
Sign up and earn $1000 a day ⋙

Leave a Comment

Instructions for fixing Task Manager has been Disabled by your Administrator

Instructions for fixing Task Manager has been Disabled by your Administrator

You may wonder why Task Manager is disabled? But don't worry! The following article will guide you through the best solutions to fix Task Manager when it is not working.

7 steps to take when your phone is stolen

7 steps to take when your phone is stolen

Thousands of tourists lose their phones every year. Here's what you need to do immediately after your phone is stolen.

Summary of Apple A18 Pro CPU information: Extremely powerful performance, AI support

Summary of Apple A18 Pro CPU information: Extremely powerful performance, AI support

The A18 Pro will serve as the successor to the A17 Pro, and is expected to power the iPhone 16 Pro and iPhone 16 Pro Max lineup.

How to save data YouTube uses

How to save data YouTube uses

The YouTube app provides several options for users to enable mobile data saver mode and you can use those options to reduce data consumption while watching videos.

Alarming Fact: Lithium Batteries Could Be an Environmental Disaster

Alarming Fact: Lithium Batteries Could Be an Environmental Disaster

Lithium batteries used in everyday devices and renewable energy storage can release more chemicals into the environment, exacerbating soil and water pollution problems.

Komodo dragon swallows turtle

Komodo dragon swallows turtle

The video shows a Komodo dragon with a terrifying bite force breaking a turtle's shell and swallowing the animal in seconds.

Enjoy this 2.5 billion pixel photo of a detailed panorama of Mars

Enjoy this 2.5 billion pixel photo of a detailed panorama of Mars

On September 14, NASA shared the most detailed image of the surface of Mars ever, along with a video that gives us a new and clearest panoramic view of the surface of the red planet.

Free Fire special characters, FF characters, special Free Fire characters

Free Fire special characters, FF characters, special Free Fire characters

To write special characters in Free Fire in the easiest way, follow the instructions in this article.

Code Slayers Unleashed April 25, 2025, Slayers Unleashed latest code 2024

Code Slayers Unleashed April 25, 2025, Slayers Unleashed latest code 2024

Enter the Slayers Unleashed code and get in-game rewards. In addition to Roblox games, mobile games like Sausage Man, Legendary Treasures... are also among the games that receive codes.

7 best apps to insert text into photos on your phone, many fonts and colors

7 best apps to insert text into photos on your phone, many fonts and colors

Writing on photos is a much better way to convey messages and express love than regular photos, which do not allow text to be inserted into the photo. Usually, photo editing applications on phones provide the feature of writing on photos with many unique fonts and styles.

Spotify Lets Users Enjoy Their Playlists by Playing Snake

Spotify Lets Users Enjoy Their Playlists by Playing Snake

Whether you're nostalgic or not, the iconic Snake game that came pre-installed on old Nokia phones is hard to forget. It still exists in countless versions today, including one from Spotify.

Why you shouldnt ditch Samsung Internet for Google Chrome?

Why you shouldnt ditch Samsung Internet for Google Chrome?

Some people decide to go with the default Internet browser that Samsung provides on Galaxy devices. It's simple, customizable, private, and packed with useful features.

How to Use Canva and ChatGPT to Create Mass Content Designs

How to Use Canva and ChatGPT to Create Mass Content Designs

Along with ChatGPT, this tutorial will show you how the Bulk Create app works in Canva. You'll be amazed at how you can create a month's worth of content in just a few minutes.

Can AI tools really compete with traditional design tools?

Can AI tools really compete with traditional design tools?

Can AI compete with traditional design tools? And when is the best time to use them?

Good quotes about human jealousy and envy

Good quotes about human jealousy and envy

Which status of jealousy and envy makes you feel the most? The article will summarize for you the best status of jealousy and envy on the Internet.