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?

Voting rights | Political participation | US government and civics | Khan Academy

Professor Brian Harvey on why not to cheat

View All

Transformations, part 2 | Multivariable calculus | Khan Academy

So in the last video, I introduced Transformations and how you can think about functions as moving points in one space to points in another. Here, I want to show an example of what that looks like when the input space is two-dimensional. This over here i…

Virtual Mindfulness Retreat with Khan Academy and Headspace

And the intention for today’s hour is really just to relax, um, just to unwind. Not a lot of information coming at you, just embodied practices. And I know that a lot of you probably have commitments at home right now, maybe kids coming in. And so really …

The Mission | Official Trailer | National Geographic Documentary Films

My friend John paid some pirates to go to an island to talk to people about Jesus, when he knew that he had no business doing that. John’s parents brought him up to be Christian. He was just, like, full of light. I had a little bit of a crush on him. You …

EPIC NOSE PICKING and why Football RULES -- IMG! #20

Master Chief loves football, and the most confused face ever. It’s a special football episode of IMG North American football. It gives you everything a guy could want: kicks to the face, kicks to the nuts, and heads up your butt. You get to pick; you can …

Renewable Energy For the People | From the Ashes

Here we are in one of the reddest cities and one of the reddest counties in one of the reddest states. But we put the silly national politics aside to do what’s best for the people we were elected to serve. The best thing to do was to sign contracts for …

Thank you to Kenn Ricci of Flexjet

2 months ago, I was sitting at my desk when I got a phone call. It was Flexjet chairman Ken Ricky. “Congratulations, you’ve been selected to be an honorary for The Living Legends of Aviation award!” Oh my, I was shocked! This is the last thing I was expec…

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

More Articles