Sangaku Pentagon and 6 Triangles

Topic:
Triangles
Sangaku Pentagon and 6 Triangles Sangaku from the Miyagai prefecture, circa 1912. 6 congruent right triangles fan out along the sides of a regular pentagon of side a. Find the length of the hypotenuse t of these triangles in terms of a. (Jill Vincent & Claire Vincent) http://geometricloci.tumblr.com/post/104611688637/sangaku-problems http://www.hermay.org/jconstant/wasan/sangaku/index.html
6 congruent right triangles fan out along the sides of a regular pentagon of side a. Find the length of the hypotenuse t of these triangles in terms of a.