yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Writing equations to represent geometric problems | Grade 8 (TX TEKS) | Khan Academy


less than 1m read
·Nov 10, 2024

We're told the perimeter of the rectangle shown is 17x units. The area of the rectangle is 15x square units. Write an equation that represents the perimeter, and also write an equation that represents the area.

So pause this video and see if you can write those two equations.

All right, now let's do this together. So let's tackle this first one. Write an equation that represents the perimeter. The perimeter is going to be the length of all of the sides. So you have this side right over here which is 4x + 2, and then you're going to add this side over here, which is 2 and a half, plus this side over here which is going to be 4x + 2 again. So, plus 4x + 2, plus this side which is going to be 2 and A2 plus 2 and a half. Well, that's going to be equal to the perimeter, which they told us is 17x units. So that is going to be equal to 17x.

And we're done! That's all they wanted; they just want us to write an equation that represents the perimeter. We don't have to solve it.

So now let's do the same thing for the area. The area of a rectangle is going to be our base times our height, or our height times our base. So we could say it's 2 and A2 * (4x + 2). Then, that's going to be our area, which they say is 15x² units. So that's equal to 15x. We could have also written it the other way; we could have said that the area, which is 15x, is equal to 2 and A2, the height, times (4x + 2).

So, a lot of different ways to approach it, but in both cases, we are now done.

More Articles

View All
How Do We Manage Loneliness?
There are no fixed environmental criteria for loneliness to occur. It can happen anywhere, even in social settings, family gatherings, and in the presence of a spouse. We can feel alone in large groups of people, but the experience of loneliness can be to…
This is Wakaliwood | Explorer
[music playing] BILLIE MINTZ: I came here to meet an extraordinary man whose vision stretches far beyond himself. This is Isaac Nabawana. OK. Action. Action. Action. BILLIE MINTZ: He’s committed to changing the country’s image by making incredibly viole…
Does Your Startup Need To Be In San Francisco?
We’re working together. We’re in the same room right now. Yes, we get to live in the same area, even though our personal decisions about where we live are wildly different. Yeah, very different lives. I don’t have a yard. I have kids too. [Music] All ri…
15 Strategies to Improve Your Problem Solving Skills
Problem solving skills are essential in all aspects of life. From tackling everyday challenges to making critical decisions at your job, the ability to analyze problems, devise effective solutions, and implement them efficiently is a valuable skill that c…
Place value blocks | Math | 4th grade | Khan Academy
What number is shown by the place value blocks? So here we have several sets of place value blocks, some with many, many, many blocks, and some with just single blocks stacked on top of each other. We want to know what number is represented by all of the…
The Fermi Paradox: Where are all the Aliens?
Liftoff from a tropical rainforest to the Edge of Time itself. James Webb begins a voyage back to the birth of the Universe. On December 25th, 2021, NASA launched the successor to the Hubble Space Telescope, the James Webb Space Telescope. Hubble has pro…