Question 31A regular octagon is to be formed by cutting equal isosceles right triangles from the corners of a square. If the square has sides of one unit, the leg of each of the triangles has length:$\dfrac{2+\sqrt2}{3}$$\dfrac{2-\sqrt2}{2}$$\dfrac{1+\sqrt2}{2}$$\dfrac{1+\sqrt2}{3}$$\dfrac{2-\sqrt2}{3}$