Question

How do you find the cross section of a cylinder with a given radius and height?

Answer 1

I've looked around and I just can't understand how to do this, though It's probably really simple. I got a 16% on my last quiz on cross sections and stuff in geometry so help would be greatly appreciated.

Answer 2

Well, gee thanks. Your help was greatly appreciated.

Answer 3

I don't normally get such bad grades. Above 85 in everything, but math... I'm just really, really bad at geometry.

Answer 4

It depends on how you cut it, actually.

Assuming you cut it down from top to bottom you'll have a rectangle as a result, the area will be H*2R

Assuming you cut it horizontally (if the cylinder is standing upright) a circle will be the result, the formula for the circle will be Pi*R²

If you cut it in any other way, things become more difficult. You'd need to know the angle at which it is cut, and multiply by the cosine, sine or tangent of the angle at which it is cut if it is cut at an angle, and if it's cut from top down (assuming the cylinder is standing upright) it also matters if you cut it right through the middle or not, as the area will decrease if you cut it any other way.

Answer 5

Some tools that may visually help you:

http://www.shodor.org/interactivate/activities/CrossSectionFlyer/

http://www.youtube.com/watch?v=YtDl-9mHm6A

Answer 6

Thank you guys!

Answer 7

@Zimmah The links were helpful and thank you for explaining.