T4 = split regular triangle in 4 equal area pieces with minimum perimeter (modified Hall)
origin of coordinates: in the middle of the base
if there are symmetries in the solution the data are given only for the significant part
border
(0, sqrt(3)/2)
(+0.5, 0)
(-0.5, 0)
vertex 1 ( 0.09738741, 0.396898262)
arc 11 ( 0, 0.014150287) 0.398709723 [centercoordinates and radius]
arc 12 ( 0.491830328, 0.014150287) 0.549619166 [centercoordinates and radius]
arc 13 (-1.299440454, 0) 1.452121314 [centercoordinates and radius]
yields the following cutlength
CL = 1.305113032