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

How to gain muscle according to experts

How to gain muscle according to experts

Building muscle takes time and the right training, but its something anyone can do. Heres how to build muscle, according to experts.

The Best Diets for Heart Health

The Best Diets for Heart Health

In addition to regular exercise and not smoking, diet is one of the best ways to protect your heart. Here are the best diets for heart health.

How to cure insomnia for pregnant women in the last 3 months

How to cure insomnia for pregnant women in the last 3 months

The third trimester is often the most difficult time to sleep during pregnancy. Here are some ways to treat insomnia in the third trimester.

Scientifically Proven Ways to Automatically Burn Calories

Scientifically Proven Ways to Automatically Burn Calories

There are many ways to lose weight without changing anything in your diet. Here are some scientifically proven automatic weight loss or calorie-burning methods that anyone can use.

All about iOS 26

All about iOS 26

Apple has introduced iOS 26 – a major update with a brand new frosted glass design, smarter experiences, and improvements to familiar apps.

Yoga exercises to treat insomnia

Yoga exercises to treat insomnia

Yoga can provide many health benefits, including better sleep. Because yoga can be relaxing and restorative, its a great way to beat insomnia after a busy day.

What is the flower of the other shore? Meaning and legend of the flower of the other shore

What is the flower of the other shore? Meaning and legend of the flower of the other shore

The flower of the other shore is a unique flower, carrying many unique meanings. So what is the flower of the other shore, is the flower of the other shore real, what is the meaning and legend of the flower of the other shore?

Healthy snacks that help you lose weight

Healthy snacks that help you lose weight

Craving for snacks but afraid of gaining weight? Dont worry, lets explore together many types of weight loss snacks that are high in fiber, low in calories without making you try to starve yourself.

What to do when you have trouble sleeping?

What to do when you have trouble sleeping?

Prioritizing a consistent sleep schedule and evening routine can help improve the quality of your sleep. Heres what you need to know to stop tossing and turning at night.

How to add a printer to Windows 10

How to add a printer to Windows 10

Adding a printer to Windows 10 is simple, although the process for wired devices will be different than for wireless devices.

The most commonly deficient nutrients in the diet

The most commonly deficient nutrients in the diet

Diet is important to our health. Yet most of our meals are lacking in these six important nutrients.

How to get beautiful nails quickly

How to get beautiful nails quickly

You want to have a beautiful, shiny, healthy nail quickly. The simple tips for beautiful nails below will be useful for you.

The best laptops for students in 2025

The best laptops for students in 2025

Students need a specific type of laptop for their studies. It should not only be powerful enough to perform well in their chosen major, but also compact and light enough to carry around all day.

Ways to reduce the risk of birth defects in the fetus

Ways to reduce the risk of birth defects in the fetus

Birth defects are something no one wants. Although they cannot be completely prevented, you can take the following steps to reduce the risk of birth defects in your baby.

How to check RAM and check RAM errors on your computer with the highest accuracy rate

How to check RAM and check RAM errors on your computer with the highest accuracy rate

As you know, RAM is a very important hardware part in a computer, acting as memory to process data and is the factor that determines the speed of a laptop or PC. In the article below, WebTech360 will introduce you to some ways to check for RAM errors using software on Windows.