卵みたいな形か。
直線OG
 y = (0.538204/0.924151) x = (tanθ) x,
 θ = 0.5273604
との交点は
 θ = t・arctan(1/t)
より
 t = ±0.464118
 r"1 = 0.6692925  r"2 = 1.494115
 b" = (r"2−r"1)/2 = 0.412411