Tag: Sangaku

Today’s puzzle is a Japanese Sangaku. Sangakus are geometrical problems on wooden tablets which were placed as offerings at Shinto shrines or Buddhist temples during the Edo period by members of all social classes. I am going to post a number of these in t...

Consider the right-angled triangle on the bottom right. The opposite side is 1 as it’s the unit length of the square. Using the tangent function, we find the length of the adjacent side of the triangle.  Therefore, we can sum up the three segments to find the side length of the equi...

Today’s Sangaku is of the first figure on a tablet hung in the Tokuraji Temple in the Miyagi Prefecture in 1909. (on the right) Two congruent intersecting circles pass through the center of the other. A blue circle is constructed to touch both circles internally and two smaller ...