# A^2 + b^2 = c^2 What does it prove?

Asked by Hawaii_Jake (33162) August 10th, 2010

What does the 47th Proposition of Euclid mean?
That humans can reason?
That the universe is comprehensible?
That mathmatics is based on linear reasoning?
That geometry rules?

Observing members: 0 Composing members: 0

That two things equal another.

truecomedian (3937)

It’s a Pythagoras’ theorem.

9doomedtodie (3113)

That mathematics are regular in ways you wouldn’t immediately notice?

Fyrius (14555)

Is math the only place to find absolutes?

truecomedian (3937)

if a b and c are the three sides of a triangle and the angle between a and b is 90 degrees, then a^2 + b^2 equals c^2

franzie (6)

You don’t need numbers to see it work. You can use cut out cardboard squares to understand it.

LuckyGuy (39099)

@worriedguy
You’d still have to measure the squares to know the combined surface area of the two squares for sides A and B is equal to that of the square for side C. You do need numbers for that.

Unless maybe you paint the two smaller squares and somehow show it takes exactly the same amount of paint to paint the third square, or something.

Fyrius (14555)

@worriedguy

Wait, you’re right.

I stand corrected. :)

Fyrius (14555)

Imagine a right triangle where A = 5, B = 6, and C (the hypotenuse) is unknown.

A^2 + B^2 = C^2
5^2 + 6^2 = C^2
25 + 36 = C^2
61 = C^2
C = sqrt(61)

jfos (7370)
Response moderated (Off-Topic)

That right triangles are governed by certain rules. More generally, if certain rules are absolutely true, there are often certain truisms that follow that are also absolutely true.

roundsquare (5517)

Ever need to get large piece of furniture through your door?

mattbrowne (31640)

@mattbrowne
is that a metaphor for anal?

truecomedian (3937)

@truecomedian
No, he’s literally talking about fitting a piece of furniture through a doorway. Math can help there sometimes.

Hawaii_Jake (33162)

@hawaii_jake – Exactly. The activity looks like this |/|

mattbrowne (31640)

or