Ex. 24: Statement I In a triangle ABC, \(\cos^2\dfrac{A}{2}\) has the value equal to \(\dfrac{s(s-a)}{abc}\)Statement II In a triangle ABC, \(\cos\dfrac{A}{2} = \sqrt{\dfrac{(s-b)(s-c)}{bc}}\), \(\cos\dfrac{B}{2} = \sqrt{\dfrac{(s-a)(s-c)}{ac}}\), \(\cos\dfrac{C}{2} = \sqrt{\dfrac{(s-a)(s-b)}{ab}}\)