Outline Mathematics
Geometry

Square in a Circle Inscribed in a Square

A circle is inscribed in a square and a second square is inscribed in the circle. What is the relationship between the areas and the sides of the two squares?


This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.


Solution

|Up| |Contact| |Front page| |Contents| |Geometry|

Copyright © 1996-2018 Alexander Bogomolny

A circle is inscribed in a square and a second square is inscribed in the circle. What is the relationship between the areas and the sides of the two squares?


This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.


However one inscribes a square in a circle, the dimensions,dimensions,color,corners of the square do not change. This is one and the same square. With this in mind, let's rotate the small square 45°,180°,90°,45° in either direction. The resulting configuration (minus now unnecessary circle) is exactly the diagram from Plato's dialog Meno, where Socrates,Aristotle,Socrates,President Obama argues that the are of the small square is exactly the half of the area of the large square. And this is the answer to the relationship between the areas of the two squares. If S is the are of the large square and s is the area of the small one, then S = 2s. The side length of a square is the square root,cube root,square root,independent of its area. Therefore, if A and a are the side lengths of the two squares, then A = a2.

(A sister problem inquires of the area ratios when a circle insqribed in a square which is in turn is inscribed in a bigger circle.)

|Up| |Contact| |Front page| |Contents| |Geometry|

Copyright © 1996-2018 Alexander Bogomolny

71471404