Complementary and supplementary angles | Angles and intersecting lines | Geometry | Khan Academy

Let's add some tools to our geometry tool belt. Here's a thorough explanation of complementary and supplementary angles, as well as definitions of adjacent and straight angles.

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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.

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[eliotheromantic]

It's been 11 years, and still, this is helping students like me all over the world! Thank you, sir. This made me get excited about math haha

[vulture]

Im doing this you know, 11 years later! the online course I'm taking for Geometry is horrible at explaining things and I remembered Khan academy is the greatest thing ever and I can listen to it without getting distracted. God's work my guy I love your team!

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Nice it help so much thx man I wish you was my math teacher

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[radhikakrishnamurthy]

I never understood supplementary and complementary angles, but now I do. :)

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[nawh]

Yeah, he's cool and hopefully is doing more! Hello, Teacher: do you offer tutorials in other math departments? Or one on one..? My nemesis in Geometry and measurement...