Volume of rectangular pyramids using cubes | Grade 7 (TX TEKS) | Khan Academy

less than 1m read

·Nov 10, 2024

We'll be exploring the volumes of rectangular pyramids today with cubes and rectangular prisms. This is a cube; all the sides are the same length. To find the volume of a cube, I can multiply the length by the width by the height. For example, if the length of the cube is five and all sides are the same, then to find the volume I would do 5 * 5 * 5 = 125 cm cubed.

I can break this prism into three rectangular pyramids that are all congruent. So now we have a cube that's actually made out of three rectangular pyramids, and we can see here that all of the rectangular pyramids are congruent. The base of each rectangular pyramid is a square. The square is the same size as one face of our cube, and they all have the same height.

Since all of these rectangular pyramids are congruent, they all have the same volume. To summarize so far, three congruent pyramids can form a cube, and the volume of one of the pyramids will be 1/3 the volume of the entire cube. This is true for all cubes, but what about other rectangular prisms where the sides have different lengths?

'The Big Short' Explained (Movie Commentary w/ @HamishHodder and Jason Hughes)

15 Lessons Rich Parents Teach Their Kids

View All

Homeroom with Sal & John Dickerson - Tuesday, October 27

Hi everyone, Sal Khan here. Welcome to the Homeroom live stream. We have a very exciting guest today. We’re gonna have John Dickerson, who works for 60 Minutes, a CBS contributing analyst, contributes to The Atlantic, and also has written “The Hardest Job…

What Forces Are Acting On You?

What are the forces acting on you right now? I want to answer this question by introducing something called a free body diagram. This is a sketch that scientists make that shows all the forces acting on an object. Each force is represented by an arrow; th…

Successful Pitch

These are the three attributes you find in every successful pitch. These are the ones that get a check, that actually start their journey funded on Shark Tank, that go into the ecosphere of Shark Tank, that get followed every year by all the networks, tha…

Bare/bear, allowed/aloud, advice/advise, break/brake | Frequently confused words | Usage | Grammar

Hello Grim Marians, hello a man, hello uh! Today, we’re going to be talking about four sets of frequently confused words, and the one that I want to begin with is “advice” and “advise.” How do we keep these two words straight? Well, first of all, “advice…

Cheetah Matchmaking: Helping Big Cats Find A Mate | Expedition Raw

One two three great stuff! I’m a cheetah matchmaker. I actively manage a stud book for cheetah in 53 different reserves across the country. So, I effectively identify which cheetah are related to each other to swap individuals between these reserves to pr…

Real Life Money Puzzles | Teacher Resources | Financial Literacy | Khan Academy

We join this episode of real life money puzzles already in progress. “Hey, Lizette.” “Yeah, BR.” “So I’m trying to work out these two offer letters.” “I know, baby. I’m so proud of you! Everybody wants to work with my boyfriend.” “Hey, no, but seriously,…

Volume of rectangular pyramids using cubes | Grade 7 (TX TEKS) | Khan Academy

More Articles