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A Closer Look at Root Rectangles

Pythagoras Theorem

Let's take a closer look at Pythagorean theorem. The surface of the hypotenuse is equal to the sum of opposite surface plus the adjacent surface.

Or another way of putting it:

The area of the tilted square = the sum of the other square areas

root_sqares_pythagoras

To give you an example: Let's say that a = 1 and b = 1

then

c2 = 12 + 12

c = √2

Proof of Pythagoras Theorem

Klick and drag in the image to see how the areas relates to each other

This is the well known Pythagoras Theorem.

You can read more about it here at Wikipedia.

Root Squares

In the example below I'm using diagonals to show the relationship between root numbers and a simple square. The image below explains how simple root number can constructed using a start square with the width and height of 1.

root sqares

Properties of root squares

Shape Dimension Comments
1 x 1 A simple square
1 X v2 Din format, 8 pointed star or octagon, European Paper size, A1, A2, A3, A4,…
1 x v3 Equilateral Triangle, sexagon, tetra ed
1 x v4 Simply 2 squares
1 x v5 Related to the "golden mean" and the pentagram or pentagon.

A closer look at 1:v2

root2_rectangle01.png

1 relates to v2 as (v2 / 2) relates to 1.

The image below shows a more complex way of dividing a square root of 2 rectangle.

root2_rectangle02.png

The ratio 1 to v2 is used in the A paper format (ISO 216 or DIN 476) because of its properties where this rectangle where the logest side cut in half has the same ratio as the larger rectangle.

root2_Acuts.png

v2 relation to the octagon.

silver_circle01.png

A closer look at 1:v3

A closer look at 1:v5

root_5sqare.png

The interesting thing about this irrational number 1.618 and 0.618 is that the unit 1 relates to 0.618 as 1.618 to 1. In acient greece this ratio was called "phi" or "f". This ratio was also know as dividing a line in the extreme and mean ratio. In more general terms this ratio is also known as the "golden mean", "golden ratio", "golden section", golden cut", "golden number, "divine proportion", …

golden_cut01.png

We can also find this "golden" number in a pentagram enclosed in a pentagon.

pentagon_pentagram.png

Here is another image showing the irrational number 1.618 or 0.618 relation to v5.

golden_circle01.png

A triangle enclosed in a circle

golden_circle02.png

From the study of phyllotaxis and the related Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...)

What is the root of root numbers?

I believe the truth behind root numbers is quite simpe, the need to have a system to measure the ground when building large structures (i.e. buildings).

Other interesting readings

Jay Hambidge, Dynamic Symmetry, ISBN 0-7661-7679-7

Ernst Mössel,

Architecture and mathematics in ancient Egypt, Corinna Rossi, web

The Web

This site, The Flagellation of Christ

Wikipedia, Pythagorean theorem

Wikipedia, Dynamic rectangle

Wikipedia, Golden ratio (1:1.618)

Wikipedia, Trigonometric_functions

Wikipedia, Silver ratio (1:v2)

Golden Section

The Golden Rectangle and the Golden Ratio

Proportions: Golden Section or Golden Mean, Modulor, Square Root of Two, Theorie and Construction

 

Copyright © Hans E Andersson 2010. All rights reserved.