Random Thoughts....

at least I'm not the only one,

I have another problem from right now actually.

circle, diameter of 1 inch - find the area

I convert to cms to make it possible because obviously 0.5 x 0.5 x pie doesn't make the right amount.

1 inch = 2.5 cms

1.25 x 1.25 x 3.14 and now I have 4.89 cm2.

convert to square inches and I have what is basically 0.75 inches....

I'm wondering how a circle can have more diameter than area :?
 
Don't convert back and forth between unit systems EVER. You'll loose enough to make your calculations off. Pick one system in the beginning (that matches your constants or the desired final system) and stay with it throughout. Convert everything once and done. Also, don't convert to a decimal until the very last step whenever possible. More losses there. The area is 0.785in^2 if the diameter is 1 in. SQUARE inches aren't the same as linear inches. There's no problem here. If you were finding the area of the square that the circle just fit inside that would be 1 in^2. Does that make more sense? Of course the area of a circle that fits inside a square with sides = 1 in (therefor diameter = 1 in) will be less than the square.
 
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Night_Hawk said:
at least I'm not the only one,

I have another problem from right now actually.

circle, diameter of 1 inch - find the area

I convert to cms to make it possible because obviously 0.5 x 0.5 x pie doesn't make the right amount.

1 inch = 2.5 cms

1.25 x 1.25 x 3.14 and now I have 4.89 cm2.

convert to square inches and I have what is basically 0.75 inches....

I'm wondering how a circle can have more diameter than area :?
Click to expand...

A) It's pi, not pie. Pie is a dessert.

B) It's not ~3/4 inches, it's 3/4 inches squared. Which is more than 3/4 inches. (And actually, it's closer to 4/5 inches.)

C) Why are you converting to cm and back? That's just a lot of extra work.
 
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LOL @ attack of sciencey/mathy folk all saying the same thing.

Also, I'd like to point out that the reason the area of the circle is "less than the diameter" (which doesn't make sense because the units are different but anyway) is the very DEFINITION of pi. Pi is a scaling factor that makes it possible to approximate the circumference/area/volume of round things as being "sorta less than" the rigidly defined dimensions of linear objects. That's what pi does, that's how geometry works.
 
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Also if you look at this image you can see why the area of a square is bigger than that of a circle with the same diameter as the square's sides.

sqcir.gif
 
Pie is delicious.

Between this thread and the foodporn post, I'm about to eat my bunny. Starving!
 
Hemihead said:
I have in the latest weeks found myself liking old ragtime music more and more. I wonder what trick my brain is pulling on me now. :?

[YOUTUBE]http://www.youtube.com/watch?v=0B04--XmZiE[/YOUTUBE]

[YOUTUBE]http://www.youtube.com/watch?v=VzDv3Eq2N54[/YOUTUBE]
Click to expand...

I was going to suggest Tom Brier when I scrolled down and saw you'd already found him. Check out his other stuff. He does some sight reading on video game music played rag style and it's absurdly good.
 
yeah, I said pie for a laugh, and I feel stupid now for forgetting the whole " circle is just a square with the corners taken off"

It makes more sense now, but when the radius is less than one whole number of whatever you are working with (inch) what is the best thing to do?

lets say the circle in 1 inch, what do I do about the radius being 0.5 and not "squaring right" (0.5x0.5= 0.25 and I can't use that)

thats why I was switching to centimetres, just to make it whole numbers.

This might be another stupid question and I'm preparing myself to get pwned
 
Why can't you use 0.25? :huh:

Also, 1.25 is not a whole number. Your conversion didn't really accomplish anything.
 
you square the radius no matter if it's a decimal or not. if it's a negative number or not.
just follow the formula pi r^2 all the time and you'll get the right answer no matter how weird the numbers might seem.
 
Night_Hawk said:
lets say the circle in 1 inch, what do I do about the radius being 0.5 and not "squaring right" (0.5x0.5= 0.25 and I can't use that)

thats why I was switching to centimetres, just to make it whole numbers.

This might be another stupid question and I'm preparing myself to get pwned
Click to expand...

What do you mean by "squaring right?" Squaring is one of the few functions you can do to ANY number, even an imaginary one. If you can give me an example what you mean here, I might be able to explain it better.
 
wait... 0.5 x 0.5 x 3.14 just gave me 0.78

is it suppposed to be 0.75 or should I start shitting bricks?

I might have been overcomplicating the whole thing now that I think of it more...
 
Night_Hawk said:
wait... 0.5 x 0.5 x 3.14 just gave me 0.78

is it suppposed to be 0.75 or should I start shitting bricks?

I might have been overcomplicating the whole thing now that I think of it more...
Click to expand...

If you're looking at my answer, I didn't round pi. I keep it in my calculator to however many dozen decimal places it keeps. Do you know how to do decimal multiplication? I've VERY confused here. Do you have a calculator? What kind?
 
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I think all of these problems stemmed from me thinking a circle with a diameter of 1 inch should have an area of 1 inch or more.

I don't know why I was thinking that.

but I'm better now. that was a good 2 hour brain fart.

and yeah, I was using a shitty mobile phone calc at the time. I just used 3.14 for pi instead of the "real pi"
 
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