/sci/ - Science & Math

[Anonymous No.11730093]

>struggling to understand pi
How does pi stay the same even when the circle changes size???

[Anonymous No.11730099]

Do you not know how ratios work?

[Anonymous No.11730119]

>>11730093

[Anonymous No.11730137]

>>11730093
C/D=pi
nC/nD=pi
a circle twice as big has twice the diameter and twice the circumference 2C/2D=pi

[Anonymous No.11730153]

Other than just explaining ration I think it's easy to understand when thinking about circumference.
Pi is how many times you need a radius to go half a circle. That tells you that pi is also the number of how many times you need the diameter to go around the entire circle. Circa 3.14.
Think of a box that's always y x y. y/y is always 1 no matter what.
Circumference = 2πr
while I don't care how this is written now as long as the constants come first, take a moment to visualize this and change the order, then you should get it.
2 and π are constants and r (radius) is the variable for your current circle, because you will either need pi twice or r twice there's a 2 in the formula but you could also just do dπ as diameter times pi to find the circumference.

[Anonymous No.11730155]

>>11730153
ratio*

[Anonymous No.11730188]

>>11730093
Pi is a ratio
Check out this video on the history of this number and all will become clear.
https://www.youtube.com/watch?v=lcIbCZR0HbU

[Anonymous No.11730251]

Wow thanks for the help guys. Was just expecting to get flamed. I understand it now :)

[Anonymous No.11730302]

>>11730119
>>11730188
The important point here is that Pi stays constant because the ratio between circumference and radius is also constant as the circle changes size. Being a ratio of two variables doesn't automatically mean that the ratio is a constant.

[Anonymous No.11730570]

Holy fuck /sci/ is garbage.

>>11730119
This does not answer OP:s question. It just states that pi is the ratio of circumference to diameter, but does NOT show that this ratio is constant, and that pi is therefore well-defined.

>>11730137
Again, you're using what you're supposed to show: C/D = pi.

>>11730153
I won't even dignify this with a proper response.

>>11730188
>wildburger

Here's a simple proof. Take any two circles with radii [math]r_1[/math] and [math]r_2[/math]. A translation followed by a dilation of [math]\frac{r_1}{r_2}[/math] shows that these two circles are similar, i.e. [math]\frac{c_1}{c_2} = \frac{r_1}{r_2}[/math], or in other words [math]\frac{c_1}{r_1} = \frac{c_2}{r_2}[/math].

[Anonymous No.11730609]

>>11730570
>Here's a simple proof.
>OP guy doesnt know what a ratio is
You are the autistic one in this case my friend.

[Anonymous No.11730625]

>>11730570
you're an idiot

[Anonymous No.11730673]

>>11730093
I am curious jet i know only 3 normal people (not different able or sth.) Who cant grasp simple geometry. 3 Out of 80 i m sure the dont get this. Maybe 6 more who cant grasp more complex topics like perspective. But if i look what people write on the net, there seem to be much more stupidity out there as 10%
Did people hide there retardation? Did the fake to be smart?

[Anonymous No.11730686]

>>11730673
And yet i dont even try to find retardation, the opposite is true and still...

[Anonymous No.11730959]

>>11730673
>Did people hide there retardation
yes. They get through high school subjects through pure memorisation. They don't understand much.

[Anonymous No.11731279]

>>11730093
Only in flat spacetimes. Try a rotating circle. Pi will change, while the diameter stays the same.

[Anonymous No.11731420]

>>11730093
measure a circle and you'll figure out it isnt even 3.142