ShmoopTube

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3D Geometry, a la Shmoop. Take a seat. Revenge of the Triangles... in

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3D... is about to begin.

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Pending a few previews. You saw it in lame-o-vision last week...

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...but now it's going to be in all three dimensions, comin' at ya.

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Suddenly, there they are - those terrifying triangles.

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Only, they're not triangles anymore... They're prisms! Horrible, gory, flesh-eating

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prisms. Ever seen light refracted through those glass

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shapes to make a rainbow?

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3D shapes have more than just length and width.

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They have depth, too. Most 3D shapes you can make by gluing a bunch

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of 2D shapes together. Be careful with the krazy-glue, though...

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...you don't wanna walk around with a cylinder glued to your head.

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A flat surface of a shape is called a face... ...the line that connects two faces is called

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an edge... ...and a point on a 3D shape is called a vertex.

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Prisms are two parallel polygons called bases with a bunch of lateral faces that connect

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them. They're named after the shape of their bases,

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so we could have... ...triangular prisms or...

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...hexagonal prisms. Cylinders are like prisms, only the bases

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are circles instead. Pyramids are like prisms, but with only one

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base. And cones are pyramids with circular bases.

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Spheres are like balls... but don't try playing basketball with one.

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They're not regulation. Those are the basic three-dimensional shapes,

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and the ones you'll probably see often. There are other ones like polyhedrons, but

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we won't blow your mind any more for the time being.

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Now that you've got a grip on basic 3D geometry... ...you can sit back, relax, and enjoy Revenge

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of the Triangles... in 3D...

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...or... try to.

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