In Japan, during Edo period (1603-1867), people wrote mathematics problems on wooden tablet. The tablet was called ‘Sangau’. When the solutions were proved, people dedicated the Sangaku to a shrine or a temple and thanked the God for the discovery of theorem and solution.
I intend to introduce various Sangaku in my blog.
First one is a Sangaku at Sachimiya shrine in Gunma prefecture. The Sangaku was dedicated to the Sachimiya shrine in 1824.
I intend to introduce various Sangaku in my blog.
First one is a Sangaku at Sachimiya shrine in Gunma prefecture. The Sangaku was dedicated to the Sachimiya shrine in 1824.
One of the problems is like this:
The three circles contact each other and also they are touching on a line, like left diagram.
The diameter of the red circle is 9cm, and the diameter of the white circle is 36cm.
Find the diameter of yellow circle.
You might have solved a similar problem in your secondary school. ✍
(I'll put the solution next time.)
The reference (Japanese): http://www.ene1.me.gunma-u.ac.jp/wasanken/
(The photo image: http://www.ene1.me.gunma-u.ac.jp/wasanken/sangak-corner/satimiya1.htm )
(I'll put the solution next time.)
The reference (Japanese): http://www.ene1.me.gunma-u.ac.jp/wasanken/
(The photo image: http://www.ene1.me.gunma-u.ac.jp/wasanken/sangak-corner/satimiya1.htm )