Let’s get familiar with the difference between lines, line segments, and rays. Hint: a ray is somewhere between a line and a line segment!

Practice this lesson yourself on KhanAcademy.org right now:

Watch the next lesson:

Missed the previous lesson?

Geometry on Khan Academy: We are surrounded by space. And that space contains lots of things. And these things have shapes. In geometry we are concerned with the nature of these shapes, how we define them, and what they teach us about the world at large–from math to architecture to biology to astronomy (and everything in between). Learning geometry is about more than just taking your medicine (“It’s good for you!”), it’s at the core of everything that exists–including you. Having said all that, some of the specific topics we’ll cover include angles, intersecting lines, right triangles, perimeter, area, volume, circles, triangles, quadrilaterals, analytic geometry, and geometric constructions. Wow. That’s a lot. To summarize: it’s difficult to imagine any area of math that is more widely used than geometry.

About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything.

For free. For everyone. Forever. #YouCanLearnAnything

Subscribe to Khan Academy’s Geometry channel:

Subscribe to Khan Academy:

Great video, thank you very much.

thank you so much, I am home schooled and your videos really helps me :/)

this takes me all the way back. back in the day. the summer of 1969

Cool

weeew

From a home school mom with a 3rd grader, THANKS!!!! Perfect supplement to my lesson with her. 🙂

ur soooo smart

I definitely didn’t learn this in elementary school. People really learn this in elementary?

What the heck is a NUMBER ROCK?

Is it hard like a rock, or hard like a rock band?

Which software do you use? Amazing Teaching and Basics.

Wait technically even a line has to start somewhere. It starts in the middle but just keeps going on forever? If I am not mistaken a line should start in the middle and that is what I think all the teachers are doing wrong so this is how a line should look The starting point being the o but still it has a start point.

/………. cooool

Thanks for helping my kids on line segmensts

thank you!!!! it help me because tomorrow is my exam

this helped me with my Homework

thank you for my homework

Yoooou’ve never seen a woman’s attitude :- that is a LINE

Your the reason I am in honors

okay… so there’s a class line, like we form in school. the whole class is already on it, we’re moving to another location. the line has a beginning and end. but since it’s moving, is it a line segment, a line or a ray? cause a line goes on forever but nobody else is hopping on. what is a moving line labeled as?

I don’t understand how to measure a line segment ,can anybody possibly comment a link?

Great job at explaining things! I have a test on this soon this really helped me understand this alot better! Keep up the awesome work!!

oh!I didn’t know that.