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?

Khan Academy Teacher Training 2018

Good Explanations Are Acts of Creativity

View All

Walking away from marriage, children, and other stuff we're supposed to have

You want someone to grow old with? You want someone to be a mother for your children, assuming you want children? And if you don’t want children, well, you probably will, and if you don’t, you’re either deluded or immature. And you might say, “Well no, th…

Gordon Bakes Using a Hot Spring | Gordon Ramsay: Uncharted

With enough salmon for the final cook, I’m off to meet a guy who’s been innovative with Iceland’s geothermal energy. I’m told he has a very unusual way of baking bread. “Hey! Hi, Captain. Very good!” “Good to see you, man.” “Good to see you! Oh boy, yo…

Moving Meat - Deleted Scene | Life Below Zero

DRO, those thoughts out there, all thought out for sure. Yeah, they’re all thought out, they need working on now. There’s freezing outside; it’s good to clear the freezer of all the caribou we’ve got. How we put some more fish in. They’re gonna have to l…

Mario's SECRET BALLS ??!! Mind Blow 4

Oh awesome, a brand new game from Sega to compete with the Nintendo Wii. Oh no! Hey Soldier, what are you doing there in the woods playing Sega? Ah, it’s a pretty big tractor. Oh, what’s this guy doing? I bet he’s going to steal it. I bet he’s going to d…

Master Stoicism in 60 Minutes: The Philosophy That Will Change Your Life

What if you wake up tomorrow morning to the shocking revelation that everything you’ve ever worked for — all your savings, investments, retirement plans, and everything else — is completely wiped out overnight? You’ve gone from having it all and living la…

Peopling the Americas

Hey Becca. Hey Kim. All right, so we’re talking about how people got to the Americas today. So when did people first arrive in North America? Was Columbus the first one? So no, he was not. You know, back in the day, people believed that actually, pre-Col…

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

More Articles