See Fig. If x is length of perpendicular drawn to it from opposite vertex of a right-angled triangle, so, length of the diagonal is
AB = y1 + y2 ......(1)
From ∆OCB y2, = xcot θ and from ∆OCA, y1, = x tanθ. Putting the values in Eq. (1), we get
AB = x(tanθ + cotθ) ......(2)
Since, length of hypotenuse = 4 (Length of perpendicular) therefore,